diff --git a/src/backend/electron/electronConfig.ts b/src/backend/electron/electronConfig.ts
index 0fc90bf23b..59dbfba4a5 100644
--- a/src/backend/electron/electronConfig.ts
+++ b/src/backend/electron/electronConfig.ts
@@ -1,7 +1,7 @@
 import { join } from "path";
 import fs from "fs";
 import { app } from "electron";
-import { moveFile } from "move-file";
+import { writeFileSafely } from "./fileHelper";
 import { BaseConfigManager, Metadata } from "@/backend/common/ConfigManager";
 import { ConfigType } from "@/type/preload";
 
@@ -23,16 +23,7 @@ export class ElectronConfigManager extends BaseConfigManager {
   }
 
   protected async save(config: ConfigType & Metadata) {
-    // ファイル書き込みに失敗したときに設定が消えないように、tempファイル書き込み後上書き移動する
-    const temp_path = `${this.configPath}.tmp`;
-    await fs.promises.writeFile(
-      temp_path,
-      JSON.stringify(config, undefined, 2),
-    );
-
-    await moveFile(temp_path, this.configPath, {
-      overwrite: true,
-    });
+    writeFileSafely(this.configPath, JSON.stringify(config, undefined, 2));
   }
 
   private get configPath(): string {
diff --git a/src/backend/electron/fileHelper.ts b/src/backend/electron/fileHelper.ts
new file mode 100644
index 0000000000..9d80ac0c44
--- /dev/null
+++ b/src/backend/electron/fileHelper.ts
@@ -0,0 +1,18 @@
+import fs from "fs";
+import { moveFileSync } from "move-file";
+
+/**
+ * 書き込みに失敗したときにファイルが消えないように、
+ * tmpファイル書き込み後、保存先ファイルに上書きする
+ */
+export function writeFileSafely(
+  path: string,
+  data: string | NodeJS.ArrayBufferView,
+) {
+  const tmpPath = `${path}.tmp`;
+  fs.writeFileSync(tmpPath, data);
+
+  moveFileSync(tmpPath, path, {
+    overwrite: true,
+  });
+}
diff --git a/src/backend/electron/main.ts b/src/backend/electron/main.ts
index 42a908ecca..463262dd6f 100644
--- a/src/backend/electron/main.ts
+++ b/src/backend/electron/main.ts
@@ -28,6 +28,7 @@ import { RuntimeInfoManager } from "./manager/RuntimeInfoManager";
 import { registerIpcMainHandle, ipcMainSendProxy, IpcMainHandle } from "./ipc";
 import { getConfigManager } from "./electronConfig";
 import { EngineAndVvppController } from "./engineAndVvppController";
+import { writeFileSafely } from "./fileHelper";
 import { failure, success } from "@/type/result";
 import { AssetTextFileNames } from "@/type/staticResources";
 import {
@@ -744,7 +745,7 @@ registerIpcMainHandle<IpcMainHandle>({
 
   WRITE_FILE: (_, { filePath, buffer }) => {
     try {
-      fs.writeFileSync(
+      writeFileSafely(
         filePath,
         new DataView(buffer instanceof Uint8Array ? buffer.buffer : buffer),
       );
diff --git a/src/backend/electron/manager/RuntimeInfoManager.ts b/src/backend/electron/manager/RuntimeInfoManager.ts
index e3ec4340ca..04683ea375 100644
--- a/src/backend/electron/manager/RuntimeInfoManager.ts
+++ b/src/backend/electron/manager/RuntimeInfoManager.ts
@@ -3,11 +3,11 @@
  * ランタイム情報には起動しているエンジンのURLなどが含まれる。
  */
 
-import fs from "fs";
 import AsyncLock from "async-lock";
 import log from "electron-log/main";
 import type { AltPortInfos } from "@/store/type";
 import { EngineId, EngineInfo } from "@/type/preload";
+import { writeFileSafely } from "@/backend/electron/fileHelper";
 
 /**
  * ランタイム情報書き出しに必要なEngineInfo
@@ -99,7 +99,7 @@ export class RuntimeInfoManager {
 
       // ファイル書き出し
       try {
-        await fs.promises.writeFile(
+        writeFileSafely(
           this.runtimeInfoPath,
           JSON.stringify(runtimeInfoFormatFor3rdParty), // FIXME: zod化する
         );