diff --git a/README.md b/README.md
index bfe83d5..9c5fb0e 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,7 @@ kdbから講義情報の取得と管理を行います。
 | PG_DATABASE | Postgres接続先のデータベース名   | twinte_course_service |
 | PG_USER     | Postgres接続に使用するユーザー名 | postgres              |
 | PG_PASSWORD | Postgres接続に使用するパスワード | postgres              |
+| LOG_LEVEL   | ログレベル fatal / error / warn / info / debug / trace / off | info              |
 
 # 開発方法
 Docker + VSCodeを推奨します。
diff --git a/package.json b/package.json
index 768c3b0..331d3ae 100755
--- a/package.json
+++ b/package.json
@@ -4,10 +4,10 @@
   "main": "index.js",
   "license": "MIT",
   "scripts": {
-    "dev": "ts-node ./src/index.ts",
+    "dev": "cross-env LOG_LEVEL=trace ts-node ./src/index.ts",
     "build": "tsc",
     "proto": "./proto-gen.sh",
-    "test": "jest --runInBand --coverage",
+    "test": "cross-env LOG_LEVEL=off jest --runInBand --coverage",
     "client": "grpcc --proto ./protos/CourseService.proto --address localhost:50051 -i",
     "lint": "eslint src/**/*.ts"
   },
@@ -36,6 +36,7 @@
   },
   "dependencies": {
     "@grpc/grpc-js": "^1.2.2",
+    "cross-env": "^7.0.3",
     "google-protobuf": "^3.14.0",
     "log4js": "^6.3.0",
     "pg": "^8.5.1",
diff --git a/src/logger.ts b/src/logger.ts
index d11b87d..556864a 100644
--- a/src/logger.ts
+++ b/src/logger.ts
@@ -2,7 +2,9 @@ import log4js from 'log4js'
 
 log4js.configure({
   appenders: { std: { type: 'stdout' } },
-  categories: { default: { appenders: ['std'], level: 'trace' } },
+  categories: {
+    default: { appenders: ['std'], level: process.env.LOG_LEVEL ?? 'info' },
+  },
 })
 
 export const logger = log4js.getLogger()
diff --git a/yarn.lock b/yarn.lock
index 7c2c26e..19d7b13 100755
--- a/yarn.lock
+++ b/yarn.lock
@@ -1535,6 +1535,13 @@ create-require@^1.1.0:
   resolved "https://registry.yarnpkg.com/create-require/-/create-require-1.1.1.tgz#c1d7e8f1e5f6cfc9ff65f9cd352d37348756c333"
   integrity sha512-dcKFX3jn0MpIaXjisoRvexIJVEKzaq7z2rZKxf+MSr9TkdmHmsU4m2lcLojrj/FHl8mk5VxMmYA+ftRkP/3oKQ==
 
+cross-env@^7.0.3:
+  version "7.0.3"
+  resolved "https://registry.yarnpkg.com/cross-env/-/cross-env-7.0.3.tgz#865264b29677dc015ba8418918965dd232fc54cf"
+  integrity sha512-+/HKd6EgcQCJGh2PSjZuUitQBQynKor4wrFbRg4DtAgS1aWO+gU52xpH7M9ScGgXSYmAVS9bIJ8EzuaGw0oNAw==
+  dependencies:
+    cross-spawn "^7.0.1"
+
 cross-spawn@^6.0.0:
   version "6.0.5"
   resolved "https://registry.yarnpkg.com/cross-spawn/-/cross-spawn-6.0.5.tgz#4a5ec7c64dfae22c3a14124dbacdee846d80cbc4"
@@ -1546,7 +1553,7 @@ cross-spawn@^6.0.0:
     shebang-command "^1.2.0"
     which "^1.2.9"
 
-cross-spawn@^7.0.0, cross-spawn@^7.0.2:
+cross-spawn@^7.0.0, cross-spawn@^7.0.1, cross-spawn@^7.0.2:
   version "7.0.3"
   resolved "https://registry.yarnpkg.com/cross-spawn/-/cross-spawn-7.0.3.tgz#f73a85b9d5d41d045551c177e2882d4ac85728a6"
   integrity sha512-iRDPJKUPVEND7dHPO8rkbOnPpyDygcDFtWjpeWNCgy8WP2rXcxXL8TskReQl6OrB2G7+UJrags1q15Fudc7G6w==