diff --git a/packages/backend/src/boot/entry.ts b/packages/backend/src/boot/entry.ts
index c729591655..2bf67207b9 100644
--- a/packages/backend/src/boot/entry.ts
+++ b/packages/backend/src/boot/entry.ts
@@ -71,7 +71,7 @@ if (!envOption.quiet) {
 // Display detail of uncaught exception
 process.on('uncaughtException', err => {
 	try {
-		logger.error(err);
+		logger.error('Uncaught exception', { error: err });
 	} catch { }
 });
 
diff --git a/packages/backend/src/boot/master.ts b/packages/backend/src/boot/master.ts
index 5ea54a1bdf..616266ab2a 100644
--- a/packages/backend/src/boot/master.ts
+++ b/packages/backend/src/boot/master.ts
@@ -65,7 +65,7 @@ export async function masterMain() {
 		//await connectDb();
 		if (config.pidFile) fs.writeFileSync(config.pidFile, process.pid.toString());
 	} catch (e) {
-		bootLogger.error('Fatal error occurred during initialization', null, true);
+		bootLogger.error('Fatal error occurred during initialization', { error: e }, true);
 		process.exit(1);
 	}
 
@@ -124,7 +124,7 @@ function loadConfigBoot(): Config {
 		config = loadConfig();
 	} catch (exception) {
 		if (typeof exception === 'string') {
-			configLogger.error(exception);
+			configLogger.error(exception, null, true);
 			process.exit(1);
 		} else if ((exception as any).code === 'ENOENT') {
 			configLogger.error('Configuration file not found', null, true);
diff --git a/packages/backend/src/core/AiService.ts b/packages/backend/src/core/AiService.ts
index 4e876495a6..4bcc8bb0aa 100644
--- a/packages/backend/src/core/AiService.ts
+++ b/packages/backend/src/core/AiService.ts
@@ -11,6 +11,8 @@ import * as nsfw from 'nsfwjs';
 import si from 'systeminformation';
 import { Mutex } from 'async-mutex';
 import { bindThis } from '@/decorators.js';
+import type Logger from '@/logger.js';
+import { LoggerService } from '@/core/LoggerService.js';
 
 const _filename = fileURLToPath(import.meta.url);
 const _dirname = dirname(_filename);
@@ -20,11 +22,14 @@ let isSupportedCpu: undefined | boolean = undefined;
 
 @Injectable()
 export class AiService {
+	private logger: Logger;
 	private model: nsfw.NSFWJS;
 	private modelLoadMutex: Mutex = new Mutex();
 
 	constructor(
+		private loggerService: LoggerService,
 	) {
+		this.logger = this.loggerService.getLogger('ai');
 	}
 
 	@bindThis
@@ -36,7 +41,7 @@ export class AiService {
 			}
 
 			if (!isSupportedCpu) {
-				console.error('This CPU cannot use TensorFlow.');
+				this.logger.error('This CPU cannot use TensorFlow.');
 				return null;
 			}
 
@@ -59,7 +64,7 @@ export class AiService {
 				image.dispose();
 			}
 		} catch (err) {
-			console.error(err);
+			this.logger.error('Failed to detect sensitive', { error: err });
 			return null;
 		}
 	}
diff --git a/packages/backend/src/core/DriveService.ts b/packages/backend/src/core/DriveService.ts
index 9328604590..73128da2d9 100644
--- a/packages/backend/src/core/DriveService.ts
+++ b/packages/backend/src/core/DriveService.ts
@@ -403,7 +403,7 @@ export class DriveService {
 				})
 			.catch(
 				err => {
-					this.registerLogger.error(`Upload Failed: key = ${key}, filename = ${filename}`, err);
+					this.registerLogger.error(`Upload Failed: key = ${key}, filename = ${filename}`, { error: err });
 				},
 			);
 	}
@@ -620,7 +620,7 @@ export class DriveService {
 						userId: user ? user.id : IsNull(),
 					}) as MiDriveFile;
 				} else {
-					this.registerLogger.error(err as Error);
+					this.registerLogger.error(`failed to register ${file.uri}`, { error: err });
 					throw err;
 				}
 			}
@@ -863,7 +863,7 @@ export class DriveService {
 		} catch (err) {
 			this.downloaderLogger.error(`Failed to create drive file: ${err}`, {
 				url: url,
-				e: err,
+				error: err,
 			});
 			throw err;
 		} finally {
diff --git a/packages/backend/src/core/EmailService.ts b/packages/backend/src/core/EmailService.ts
index bf917e8038..da5e183a30 100644
--- a/packages/backend/src/core/EmailService.ts
+++ b/packages/backend/src/core/EmailService.ts
@@ -148,7 +148,7 @@ export class EmailService {
 
 			this.logger.info(`Message sent: ${info.messageId}`);
 		} catch (err) {
-			this.logger.error(err as Error);
+			this.logger.error('Failed to send email', { error: err });
 			throw err;
 		}
 	}
@@ -286,18 +286,18 @@ export class EmailService {
 					Authorization: truemailAuthKey
 				},
 			});
-			
+
 			const json = (await res.json()) as {
 				email: string;
 				success: boolean;
-				errors?: { 
+				errors?: {
 					list_match?: string;
 					regex?: string;
 					mx?: string;
 					smtp?: string;
 				} | null;
 			};
-			
+
 			if (json.email === undefined || (json.email !== undefined && json.errors?.regex)) {
 				return {
 						valid: false,
@@ -322,7 +322,7 @@ export class EmailService {
 					reason: json.errors?.list_match as T || 'blacklist',
 				};
 			}
-			
+
 			return {
 				valid: true,
 				reason: null,
diff --git a/packages/backend/src/core/FetchInstanceMetadataService.ts b/packages/backend/src/core/FetchInstanceMetadataService.ts
index 7abf8370d3..b9e9a71131 100644
--- a/packages/backend/src/core/FetchInstanceMetadataService.ts
+++ b/packages/backend/src/core/FetchInstanceMetadataService.ts
@@ -116,7 +116,7 @@ export class FetchInstanceMetadataService {
 
 			this.logger.succ(`Successfuly updated metadata of ${instance.host}`);
 		} catch (e) {
-			this.logger.error(`Failed to update metadata of ${instance.host}: ${e}`);
+			this.logger.error(`Failed to update metadata of ${instance.host}: ${e}`, { error: e });
 		} finally {
 			await this.unlock(host);
 		}
@@ -160,7 +160,7 @@ export class FetchInstanceMetadataService {
 
 			return info as NodeInfo;
 		} catch (err) {
-			this.logger.error(`Failed to fetch nodeinfo of ${instance.host}: ${err}`);
+			this.logger.error(`Failed to fetch nodeinfo of ${instance.host}: ${err}`, { error: err });
 
 			throw err;
 		}
diff --git a/packages/backend/src/core/NoteCreateService.ts b/packages/backend/src/core/NoteCreateService.ts
index 36a00af01d..1a0e72748d 100644
--- a/packages/backend/src/core/NoteCreateService.ts
+++ b/packages/backend/src/core/NoteCreateService.ts
@@ -32,10 +32,12 @@ import { RelayService } from '@/core/RelayService.js';
 import { FederatedInstanceService } from '@/core/FederatedInstanceService.js';
 import { DI } from '@/di-symbols.js';
 import type { Config } from '@/config.js';
+import type Logger from '@/logger.js';
 import NotesChart from '@/core/chart/charts/notes.js';
 import PerUserNotesChart from '@/core/chart/charts/per-user-notes.js';
 import InstanceChart from '@/core/chart/charts/instance.js';
 import ActiveUsersChart from '@/core/chart/charts/active-users.js';
+import { LoggerService } from '@/core/LoggerService.js';
 import { GlobalEventService } from '@/core/GlobalEventService.js';
 import { NotificationService } from '@/core/NotificationService.js';
 import { WebhookService } from '@/core/WebhookService.js';
@@ -149,6 +151,7 @@ type Option = {
 
 @Injectable()
 export class NoteCreateService implements OnApplicationShutdown {
+	private logger: Logger;
 	#shutdownController = new AbortController();
 
 	constructor(
@@ -217,7 +220,10 @@ export class NoteCreateService implements OnApplicationShutdown {
 		private instanceChart: InstanceChart,
 		private utilityService: UtilityService,
 		private userBlockingService: UserBlockingService,
-	) { }
+		private loggerService: LoggerService,
+	) {
+		this.logger = this.loggerService.getLogger('note:create');
+	}
 
 	@bindThis
 	public async create(user: {
@@ -472,7 +478,7 @@ export class NoteCreateService implements OnApplicationShutdown {
 				throw err;
 			}
 
-			console.error(e);
+			this.logger.error(`Failed to create note: ${e}`, { error: e });
 
 			throw e;
 		}
diff --git a/packages/backend/src/core/RemoteUserResolveService.ts b/packages/backend/src/core/RemoteUserResolveService.ts
index 75c5f14aa4..77ac5a4ad5 100644
--- a/packages/backend/src/core/RemoteUserResolveService.ts
+++ b/packages/backend/src/core/RemoteUserResolveService.ts
@@ -145,7 +145,7 @@ export class RemoteUserResolveService {
 	private async resolveSelf(acctLower: string): Promise<ILink> {
 		this.logger.info(`WebFinger for ${chalk.yellow(acctLower)}`);
 		const finger = await this.webfingerService.webfinger(acctLower).catch(err => {
-			this.logger.error(`Failed to WebFinger for ${chalk.yellow(acctLower)}: ${ err.statusCode ?? err.message }`);
+			this.logger.error(`Failed to WebFinger for ${chalk.yellow(acctLower)}: ${ err.statusCode ?? err.message }`, { error: err });
 			throw new Error(`Failed to WebFinger for ${acctLower}: ${ err.statusCode ?? err.message }`);
 		});
 		const self = finger.links.find(link => link.rel != null && link.rel.toLowerCase() === 'self');
diff --git a/packages/backend/src/core/WebAuthnService.ts b/packages/backend/src/core/WebAuthnService.ts
index 7b2cf8467a..ae63701f90 100644
--- a/packages/backend/src/core/WebAuthnService.ts
+++ b/packages/backend/src/core/WebAuthnService.ts
@@ -15,8 +15,10 @@ import { AttestationFormat, isoCBOR } from '@simplewebauthn/server/helpers';
 import { DI } from '@/di-symbols.js';
 import type { UserSecurityKeysRepository } from '@/models/_.js';
 import type { Config } from '@/config.js';
+import type Logger from '@/logger.js';
 import { bindThis } from '@/decorators.js';
 import { MetaService } from '@/core/MetaService.js';
+import { LoggerService } from '@/core/LoggerService.js';
 import { MiUser } from '@/models/_.js';
 import { IdentifiableError } from '@/misc/identifiable-error.js';
 import type {
@@ -31,6 +33,8 @@ import type {
 
 @Injectable()
 export class WebAuthnService {
+	private logger: Logger;
+
 	constructor(
 		@Inject(DI.redis)
 		private redisClient: Redis.Redis,
@@ -42,7 +46,9 @@ export class WebAuthnService {
 		private userSecurityKeysRepository: UserSecurityKeysRepository,
 
 		private metaService: MetaService,
+		private loggerService: LoggerService,
 	) {
+		this.logger = this.loggerService.getLogger('webauthn');
 	}
 
 	@bindThis
@@ -118,7 +124,7 @@ export class WebAuthnService {
 				requireUserVerification: true,
 			});
 		} catch (error) {
-			console.error(error);
+			this.logger.error('Failed to verify registration response', { error });
 			throw new IdentifiableError('5c1446f8-8ca7-4d31-9f39-656afe9c5d87', 'verification failed');
 		}
 
@@ -228,7 +234,7 @@ export class WebAuthnService {
 				requireUserVerification: true,
 			});
 		} catch (error) {
-			console.error(error);
+			this.logger.error('Failed to verify authentication response', { error });
 			throw new IdentifiableError('b18c89a7-5b5e-4cec-bb5b-0419f332d430', 'verification failed');
 		}
 
diff --git a/packages/backend/src/core/activitypub/ApInboxService.ts b/packages/backend/src/core/activitypub/ApInboxService.ts
index 6b660de150..85a7f549a0 100644
--- a/packages/backend/src/core/activitypub/ApInboxService.ts
+++ b/packages/backend/src/core/activitypub/ApInboxService.ts
@@ -197,7 +197,7 @@ export class ApInboxService {
 		const resolver = this.apResolverService.createResolver();
 
 		const object = await resolver.resolve(activity.object).catch(err => {
-			this.logger.error(`Resolution failed: ${err}`);
+			this.logger.error(`Resolution failed: ${err}`, { error: err });
 			throw err;
 		});
 
@@ -370,7 +370,7 @@ export class ApInboxService {
 		const resolver = this.apResolverService.createResolver();
 
 		const object = await resolver.resolve(activity.object).catch(e => {
-			this.logger.error(`Resolution failed: ${e}`);
+			this.logger.error(`Resolution failed: ${e}`, { error: e });
 			throw e;
 		});
 
@@ -544,7 +544,7 @@ export class ApInboxService {
 		const resolver = this.apResolverService.createResolver();
 
 		const object = await resolver.resolve(activity.object).catch(e => {
-			this.logger.error(`Resolution failed: ${e}`);
+			this.logger.error(`Resolution failed: ${e}`, { error: e });
 			throw e;
 		});
 
@@ -610,7 +610,7 @@ export class ApInboxService {
 		const resolver = this.apResolverService.createResolver();
 
 		const object = await resolver.resolve(activity.object).catch(e => {
-			this.logger.error(`Resolution failed: ${e}`);
+			this.logger.error(`Resolution failed: ${e}`, { error: e });
 			throw e;
 		});
 
@@ -741,7 +741,7 @@ export class ApInboxService {
 		const resolver = this.apResolverService.createResolver();
 
 		const object = await resolver.resolve(activity.object).catch(e => {
-			this.logger.error(`Resolution failed: ${e}`);
+			this.logger.error(`Resolution failed: ${e}`, { error: e });
 			throw e;
 		});
 
@@ -749,7 +749,7 @@ export class ApInboxService {
 			await this.apPersonService.updatePerson(actor.uri, resolver, object);
 			return 'ok: Person updated';
 		} else if (getApType(object) === 'Question') {
-			await this.apQuestionService.updateQuestion(object, resolver).catch(err => console.error(err));
+			await this.apQuestionService.updateQuestion(object, resolver).catch(err => this.logger.error(`err: failed to update question: ${err}`, { error: err }));
 			return 'ok: Question updated';
 		} else {
 			return `skip: Unknown type: ${getApType(object)}`;
diff --git a/packages/backend/src/core/activitypub/models/ApNoteService.ts b/packages/backend/src/core/activitypub/models/ApNoteService.ts
index 458dfaa7b1..1d00bf0cca 100644
--- a/packages/backend/src/core/activitypub/models/ApNoteService.ts
+++ b/packages/backend/src/core/activitypub/models/ApNoteService.ts
@@ -126,6 +126,7 @@ export class ApNoteService {
 				resolver: { history: resolver.getHistory() },
 				value,
 				object,
+				error: err
 			});
 			throw new Error('invalid note');
 		}
diff --git a/packages/backend/src/core/activitypub/models/ApPersonService.ts b/packages/backend/src/core/activitypub/models/ApPersonService.ts
index 2c11f4c07f..b1becbabab 100644
--- a/packages/backend/src/core/activitypub/models/ApPersonService.ts
+++ b/packages/backend/src/core/activitypub/models/ApPersonService.ts
@@ -301,7 +301,7 @@ export class ApPersonService implements OnModuleInit {
 		const emojis = await this.apNoteService.extractEmojis(person.tag ?? [], host)
 			.then(_emojis => _emojis.map(emoji => emoji.name))
 			.catch(err => {
-				this.logger.error('error occurred while fetching user emojis', { stack: err });
+				this.logger.error('error occurred while fetching user emojis', { error: err });
 				return [];
 			});
 		//#endregion
@@ -369,7 +369,7 @@ export class ApPersonService implements OnModuleInit {
 
 				user = u as MiRemoteUser;
 			} else {
-				this.logger.error(e instanceof Error ? e : new Error(e as string));
+				this.logger.error('error occurred while creating user', { error: e });
 				throw e;
 			}
 		}
@@ -402,7 +402,7 @@ export class ApPersonService implements OnModuleInit {
 			// Register to the cache
 			this.cacheService.uriPersonCache.set(user.uri, user);
 		} catch (err) {
-			this.logger.error('error occurred while fetching user avatar/banner', { stack: err });
+			this.logger.error('error occurred while fetching user avatar/banner', { error: err });
 		}
 		//#endregion
 
diff --git a/packages/backend/src/logger.ts b/packages/backend/src/logger.ts
index 535c84db9f..1d442cd65b 100644
--- a/packages/backend/src/logger.ts
+++ b/packages/backend/src/logger.ts
@@ -88,16 +88,25 @@ export default class Logger {
 		if (data != null) {
 			args.push(data);
 		}
-		console.log(...args);
+
+		if (level === 'error' || level === 'warning') {
+			console.error(...args);
+		} else {
+			console.log(...args);
+		}
 	}
 
 	@bindThis
 	public error(x: string | Error, data?: Record<string, any> | null, important = false): void { // 実行を継続できない状況で使う
 		if (x instanceof Error) {
 			data = data ?? {};
-			data.e = x;
+			data.error = x;
+
 			this.log('error', x.toString(), data, important);
 		} else if (typeof x === 'object') {
+			data = data ?? {};
+			data.error = data.error ?? x;
+
 			this.log('error', `${(x as any).message ?? (x as any).name ?? x}`, data, important);
 		} else {
 			this.log('error', `${x}`, data, important);
@@ -105,8 +114,20 @@ export default class Logger {
 	}
 
 	@bindThis
-	public warn(message: string, data?: Record<string, any> | null, important = false): void { // 実行を継続できるが改善すべき状況で使う
-		this.log('warning', message, data, important);
+	public warn(x: string | Error, data?: Record<string, any> | null, important = false): void { // 実行を継続できるが改善すべき状況で使う
+		if (x instanceof Error) {
+			data = data ?? {};
+			data.error = x;
+
+			this.log('warning', x.toString(), data, important);
+		} else if (typeof x === 'object') {
+			data = data ?? {};
+			data.error = data.error ?? x;
+
+			this.log('warning', `${(x as any).message ?? (x as any).name ?? x}`, data, important);
+		} else {
+			this.log('warning', `${x}`, data, important);
+		}
 	}
 
 	@bindThis
diff --git a/packages/backend/src/queue/QueueProcessorService.ts b/packages/backend/src/queue/QueueProcessorService.ts
index 7f65c66429..b89827d430 100644
--- a/packages/backend/src/queue/QueueProcessorService.ts
+++ b/packages/backend/src/queue/QueueProcessorService.ts
@@ -157,8 +157,8 @@ export class QueueProcessorService implements OnApplicationShutdown {
 		this.systemQueueWorker
 			.on('active', (job) => systemLogger.debug(`active id=${job.id}`))
 			.on('completed', (job, result) => systemLogger.debug(`completed(${result}) id=${job.id}`))
-			.on('failed', (job, err) => systemLogger.warn(`failed(${err.stack}) id=${job ? job.id : '-'}`, { job, e: renderError(err) }))
-			.on('error', (err: Error) => systemLogger.error(`error ${err.stack}`, { e: renderError(err) }))
+			.on('failed', (job, err) => systemLogger.warn(`failed(${err.stack}) id=${job ? job.id : '-'}`, { job, error: renderError(err) }))
+			.on('error', (err: Error) => systemLogger.error(`error ${err.stack}`, { error: renderError(err) }))
 			.on('stalled', (jobId) => systemLogger.warn(`stalled id=${jobId}`));
 		//#endregion
 
@@ -197,8 +197,8 @@ export class QueueProcessorService implements OnApplicationShutdown {
 		this.dbQueueWorker
 			.on('active', (job) => dbLogger.debug(`active id=${job.id}`))
 			.on('completed', (job, result) => dbLogger.debug(`completed(${result}) id=${job.id}`))
-			.on('failed', (job, err) => dbLogger.warn(`failed(${err.stack}) id=${job ? job.id : '-'}`, { job, e: renderError(err) }))
-			.on('error', (err: Error) => dbLogger.error(`error ${err.stack}`, { e: renderError(err) }))
+			.on('failed', (job, err) => dbLogger.warn(`failed(${err.stack}) id=${job ? job.id : '-'}`, { job, error: renderError(err) }))
+			.on('error', (err: Error) => dbLogger.error(`error ${err.stack}`, { error: renderError(err) }))
 			.on('stalled', (jobId) => dbLogger.warn(`stalled id=${jobId}`));
 		//#endregion
 
@@ -222,7 +222,7 @@ export class QueueProcessorService implements OnApplicationShutdown {
 			.on('active', (job) => deliverLogger.debug(`active ${getJobInfo(job, true)} to=${job.data.to}`))
 			.on('completed', (job, result) => deliverLogger.debug(`completed(${result}) ${getJobInfo(job, true)} to=${job.data.to}`))
 			.on('failed', (job, err) => deliverLogger.warn(`failed(${err.stack}) ${getJobInfo(job)} to=${job ? job.data.to : '-'}`))
-			.on('error', (err: Error) => deliverLogger.error(`error ${err.stack}`, { e: renderError(err) }))
+			.on('error', (err: Error) => deliverLogger.error(`error ${err.stack}`, { error: renderError(err) }))
 			.on('stalled', (jobId) => deliverLogger.warn(`stalled id=${jobId}`));
 		//#endregion
 
@@ -245,8 +245,8 @@ export class QueueProcessorService implements OnApplicationShutdown {
 		this.inboxQueueWorker
 			.on('active', (job) => inboxLogger.debug(`active ${getJobInfo(job, true)}`))
 			.on('completed', (job, result) => inboxLogger.debug(`completed(${result}) ${getJobInfo(job, true)}`))
-			.on('failed', (job, err) => inboxLogger.warn(`failed(${err.stack}) ${getJobInfo(job)} activity=${job ? (job.data.activity ? job.data.activity.id : 'none') : '-'}`, { job, e: renderError(err) }))
-			.on('error', (err: Error) => inboxLogger.error(`error ${err.stack}`, { e: renderError(err) }))
+			.on('failed', (job, err) => inboxLogger.warn(`failed(${err.stack}) ${getJobInfo(job)} activity=${job ? (job.data.activity ? job.data.activity.id : 'none') : '-'}`, { job, error: renderError(err) }))
+			.on('error', (err: Error) => inboxLogger.error(`error ${err.stack}`, { error: renderError(err) }))
 			.on('stalled', (jobId) => inboxLogger.warn(`stalled id=${jobId}`));
 		//#endregion
 
@@ -270,7 +270,7 @@ export class QueueProcessorService implements OnApplicationShutdown {
 			.on('active', (job) => webhookLogger.debug(`active ${getJobInfo(job, true)} to=${job.data.to}`))
 			.on('completed', (job, result) => webhookLogger.debug(`completed(${result}) ${getJobInfo(job, true)} to=${job.data.to}`))
 			.on('failed', (job, err) => webhookLogger.warn(`failed(${err.stack}) ${getJobInfo(job)} to=${job ? job.data.to : '-'}`))
-			.on('error', (err: Error) => webhookLogger.error(`error ${err.stack}`, { e: renderError(err) }))
+			.on('error', (err: Error) => webhookLogger.error(`error ${err.stack}`, { error: renderError(err) }))
 			.on('stalled', (jobId) => webhookLogger.warn(`stalled id=${jobId}`));
 		//#endregion
 
@@ -298,8 +298,8 @@ export class QueueProcessorService implements OnApplicationShutdown {
 		this.relationshipQueueWorker
 			.on('active', (job) => relationshipLogger.debug(`active id=${job.id}`))
 			.on('completed', (job, result) => relationshipLogger.debug(`completed(${result}) id=${job.id}`))
-			.on('failed', (job, err) => relationshipLogger.warn(`failed(${err.stack}) id=${job ? job.id : '-'}`, { job, e: renderError(err) }))
-			.on('error', (err: Error) => relationshipLogger.error(`error ${err.stack}`, { e: renderError(err) }))
+			.on('failed', (job, err) => relationshipLogger.warn(`failed(${err.stack}) id=${job ? job.id : '-'}`, { job, error: renderError(err) }))
+			.on('error', (err: Error) => relationshipLogger.error(`error ${err.stack}`, { error: renderError(err) }))
 			.on('stalled', (jobId) => relationshipLogger.warn(`stalled id=${jobId}`));
 		//#endregion
 
@@ -321,8 +321,8 @@ export class QueueProcessorService implements OnApplicationShutdown {
 		this.objectStorageQueueWorker
 			.on('active', (job) => objectStorageLogger.debug(`active id=${job.id}`))
 			.on('completed', (job, result) => objectStorageLogger.debug(`completed(${result}) id=${job.id}`))
-			.on('failed', (job, err) => objectStorageLogger.warn(`failed(${err.stack}) id=${job ? job.id : '-'}`, { job, e: renderError(err) }))
-			.on('error', (err: Error) => objectStorageLogger.error(`error ${err.stack}`, { e: renderError(err) }))
+			.on('failed', (job, err) => objectStorageLogger.warn(`failed(${err.stack}) id=${job ? job.id : '-'}`, { job, error: renderError(err) }))
+			.on('error', (err: Error) => objectStorageLogger.error(`error ${err.stack}`, { error: renderError(err) }))
 			.on('stalled', (jobId) => objectStorageLogger.warn(`stalled id=${jobId}`));
 		//#endregion
 
diff --git a/packages/backend/src/queue/processors/ExportCustomEmojisProcessorService.ts b/packages/backend/src/queue/processors/ExportCustomEmojisProcessorService.ts
index d5387fe42e..f08c9c6bf9 100644
--- a/packages/backend/src/queue/processors/ExportCustomEmojisProcessorService.ts
+++ b/packages/backend/src/queue/processors/ExportCustomEmojisProcessorService.ts
@@ -99,7 +99,7 @@ export class ExportCustomEmojisProcessorService {
 				await this.downloadService.downloadUrl(emoji.originalUrl, emojiPath);
 				downloaded = true;
 			} catch (e) { // TODO: 何度か再試行
-				this.logger.error(e instanceof Error ? e : new Error(e as string));
+				this.logger.error(`Failed to download emoji '${emoji.name}': ${emoji.originalUrl}`, { error: e });
 			}
 
 			if (!downloaded) {
diff --git a/packages/backend/src/server/FileServerService.ts b/packages/backend/src/server/FileServerService.ts
index f59996ce17..8afac39907 100644
--- a/packages/backend/src/server/FileServerService.ts
+++ b/packages/backend/src/server/FileServerService.ts
@@ -96,7 +96,7 @@ export class FileServerService {
 
 	@bindThis
 	private async errorHandler(request: FastifyRequest<{ Params?: { [x: string]: any }; Querystring?: { [x: string]: any }; }>, reply: FastifyReply, err?: any) {
-		this.logger.error(`${err}`);
+		this.logger.error('file server error', { error: err });
 
 		reply.header('Cache-Control', 'max-age=300');
 
diff --git a/packages/backend/src/server/api/ApiCallService.ts b/packages/backend/src/server/api/ApiCallService.ts
index 916dc11eda..c089bbbb13 100644
--- a/packages/backend/src/server/api/ApiCallService.ts
+++ b/packages/backend/src/server/api/ApiCallService.ts
@@ -371,14 +371,13 @@ export class ApiCallService implements OnApplicationShutdown {
 				this.logger.error(`Internal error occurred in ${ep.name}: ${err.message}`, {
 					ep: ep.name,
 					ps: data,
-					e: {
+					id: errId,
+					error: {
 						message: err.message,
 						code: err.name,
 						stack: err.stack,
-						id: errId,
 					},
 				});
-				console.error(err, errId);
 				throw new ApiError(null, {
 					e: {
 						message: err.message,
diff --git a/packages/backend/src/server/api/endpoints/drive/files/create.ts b/packages/backend/src/server/api/endpoints/drive/files/create.ts
index bae62d264a..59eff00370 100644
--- a/packages/backend/src/server/api/endpoints/drive/files/create.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files/create.ts
@@ -6,10 +6,12 @@
 import ms from 'ms';
 import { Injectable } from '@nestjs/common';
 import { DB_MAX_IMAGE_COMMENT_LENGTH } from '@/const.js';
+import type Logger from '@/logger.js';
 import { IdentifiableError } from '@/misc/identifiable-error.js';
 import { Endpoint } from '@/server/api/endpoint-base.js';
 import { DriveFileEntityService } from '@/core/entities/DriveFileEntityService.js';
 import { MetaService } from '@/core/MetaService.js';
+import { LoggerService } from '@/core/LoggerService.js';
 import { DriveService } from '@/core/DriveService.js';
 import { ApiError } from '../../../error.js';
 
@@ -73,9 +75,12 @@ export const paramDef = {
 
 @Injectable()
 export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-disable-line import/no-default-export
+	private logger: Logger;
+
 	constructor(
 		private driveFileEntityService: DriveFileEntityService,
 		private metaService: MetaService,
+		private loggerService: LoggerService,
 		private driveService: DriveService,
 	) {
 		super(meta, paramDef, async (ps, me, _, file, cleanup, ip, headers) => {
@@ -109,9 +114,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				});
 				return await this.driveFileEntityService.pack(driveFile, me, { self: true });
 			} catch (err) {
-				if (err instanceof Error || typeof err === 'string') {
-					console.error(err);
-				}
+				this.logger.error('Failed to create drive file', { error: err });
 				if (err instanceof IdentifiableError) {
 					if (err.id === '282f77bf-5816-4f72-9264-aa14d8261a21') throw new ApiError(meta.errors.inappropriate);
 					if (err.id === 'c6244ed2-a39a-4e1c-bf93-f0fbd7764fa6') throw new ApiError(meta.errors.noFreeSpace);
@@ -121,5 +124,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 				cleanup!();
 			}
 		});
+
+		this.logger = this.loggerService.getLogger('api:drive:files:create');
 	}
 }
diff --git a/packages/backend/src/server/oauth/OAuth2ProviderService.ts b/packages/backend/src/server/oauth/OAuth2ProviderService.ts
index 2253078582..bef5034ee7 100644
--- a/packages/backend/src/server/oauth/OAuth2ProviderService.ts
+++ b/packages/backend/src/server/oauth/OAuth2ProviderService.ts
@@ -138,8 +138,7 @@ async function discoverClientInformation(logger: Logger, httpRequestService: Htt
 			name: typeof name === 'string' ? name : id,
 		};
 	} catch (err) {
-		console.error(err);
-		logger.error('Error while fetching client information', { err });
+		logger.error('Error while fetching client information', { error: err });
 		if (err instanceof StatusError) {
 			throw new AuthorizationError('Failed to fetch client information', 'invalid_request');
 		} else {
diff --git a/packages/backend/src/server/web/ClientServerService.ts b/packages/backend/src/server/web/ClientServerService.ts
index aac4cfeada..df2fff4614 100644
--- a/packages/backend/src/server/web/ClientServerService.ts
+++ b/packages/backend/src/server/web/ClientServerService.ts
@@ -783,9 +783,8 @@ export class ClientServerService {
 				path: request.routeOptions.url,
 				params: request.params,
 				query: request.query,
-				code: error.name,
-				stack: error.stack,
 				id: errId,
+				error,
 			});
 			reply.code(500);
 			reply.header('Cache-Control', 'max-age=10, must-revalidate');
diff --git a/packages/backend/test/unit/FileInfoService.ts b/packages/backend/test/unit/FileInfoService.ts
index f3717d73cd..fbd1539f13 100644
--- a/packages/backend/test/unit/FileInfoService.ts
+++ b/packages/backend/test/unit/FileInfoService.ts
@@ -12,6 +12,7 @@ import { ModuleMocker } from 'jest-mock';
 import { Test } from '@nestjs/testing';
 import { afterAll, beforeAll, describe, test } from '@jest/globals';
 import { GlobalModule } from '@/GlobalModule.js';
+import { LoggerService } from '@/core/LoggerService.js';
 import { FileInfoService } from '@/core/FileInfoService.js';
 //import { DI } from '@/di-symbols.js';
 import { AiService } from '@/core/AiService.js';
@@ -34,6 +35,7 @@ describe('FileInfoService', () => {
 				GlobalModule,
 			],
 			providers: [
+				LoggerService,
 				AiService,
 				FileInfoService,
 			],