diff --git a/i18n/locales/en.json b/i18n/locales/en.json
index 16a1653..4542cec 100644
--- a/i18n/locales/en.json
+++ b/i18n/locales/en.json
@@ -25,5 +25,6 @@
   "ソースコードを非表示": "Hide source code",
   "エラーの詳細を見る": "Click to view error details",
   "クリックして閉じる": "Click to close",
-  "コマンド": "Command"
+  "コマンド": "Command",
+  "検証": "Verify"
 }
diff --git a/i18n/locales/ja.json b/i18n/locales/ja.json
index 3d4d49c..4173d63 100644
--- a/i18n/locales/ja.json
+++ b/i18n/locales/ja.json
@@ -25,5 +25,6 @@
   "ソースコードを非表示": "ソースコードを非表示",
   "エラーの詳細を見る": "エラーの詳細を見る",
   "クリックして閉じる": "クリックして閉じる",
-  "コマンド": "コマンド"
+  "コマンド": "コマンド",
+  "検証": "検証"
 }
diff --git a/src/hooks/useCrc8.ts b/src/hooks/useCrc8.ts
new file mode 100644
index 0000000..730146e
--- /dev/null
+++ b/src/hooks/useCrc8.ts
@@ -0,0 +1,6 @@
+import { useMemo } from "react";
+import { crc8Calculator } from "../utils/crc8Calculator";
+
+export const useCrc8 = (data?: Uint8Array) => {
+  return useMemo(() => crc8Calculator(data), [data]);
+};
diff --git a/src/libs/mrubyWriterConnector.ts b/src/libs/mrubyWriterConnector.ts
index 8c75780..21db8e6 100644
--- a/src/libs/mrubyWriterConnector.ts
+++ b/src/libs/mrubyWriterConnector.ts
@@ -1,4 +1,5 @@
 import { WritableStreamDefaultWriter } from "stream/web";
+import { crc8Calculator } from "../utils/crc8Calculator";
 import { Failure, Result, Success } from "./result";
 
 export const targets = ["ESP32", "RBoard"] as const;
@@ -23,7 +24,7 @@ const enterWriteModeKeyword: Record<Target, RegExp> = {
 } as const;
 
 const exitWriteModeKeyword: Record<Target, RegExp> = {
-  ESP32: /mrubyc-esp32: End mrbwrite mode/,
+  ESP32: /mruby\/c v\d(.\d+)* start/,
   RBoard: /\+OK Execute mruby\/c\./,
 } as const;
 
@@ -238,7 +239,7 @@ export class MrubyWriterConnector {
   async writeCode(
     binary: Uint8Array,
     option?: Partial<{ execute: boolean }>
-  ): Promise<Result<null, Error>> {
+  ): Promise<Result<string, Error>> {
     if (!this.port) {
       return Failure.error("No port.");
     }
@@ -262,7 +263,11 @@ export class MrubyWriterConnector {
       await this.sendCommand("execute");
     }
 
-    return Success.value(null);
+    const crc = crc8Calculator(binary);
+    const crcRes = writeRes.value.split("+OK")[1];
+    if (crc !== undefined && crcRes !== undefined)
+      this.verify(crc, parseInt(crcRes, 16));
+    return Success.value(writeRes.value);
   }
 
   private async sendData(
@@ -492,4 +497,13 @@ export class MrubyWriterConnector {
 
     return Success.value(line);
   }
+  async verify(culcHash: number, retHash: number) {
+    if (culcHash === retHash) {
+      this.handleText("\r\n Verify Success\r\n");
+      return true;
+    } else {
+      this.handleText("\r\n Verify Failed\r\n");
+      return false;
+    }
+  }
 }
diff --git a/src/pages/home.tsx b/src/pages/home.tsx
index 491f65a..ad11087 100644
--- a/src/pages/home.tsx
+++ b/src/pages/home.tsx
@@ -2,6 +2,7 @@ import {
   CheckCircleRounded as CheckCircleRoundedIcon,
   Edit as EditIcon,
   Flag as FlagIcon,
+  Plagiarism,
   Usb as UsbIcon,
   UsbOff as UsbOffIcon,
 } from "@mui/icons-material";
@@ -30,6 +31,7 @@ import { isTarget } from "libs/utility";
 import { useTranslation } from "react-i18next";
 import ESP32 from "/images/ESP32.png";
 import RBoard from "/images/Rboard.png";
+import { useCrc8 } from "../hooks/useCrc8";
 
 const targets = [
   {
@@ -51,6 +53,7 @@ const commands = [
   "reset",
   "help",
   "showprog",
+  "verify",
 ] as const;
 
 export const Home = () => {
@@ -98,6 +101,7 @@ export const Home = () => {
     }
   }, [t, connector]);
 
+  const crc8 = useCrc8(code);
   //１秒ごとに書き込みモードに入ることを試みる
   const tryEntry = useCallback(async () => {
     return new Promise<void>((resolve, reject) => {
@@ -159,8 +163,13 @@ export const Home = () => {
           }`
         );
       }
+      if (text == "verify" && res.isSuccess() && res.value.includes("+OK")) {
+        const hash = parseInt(res.value.split("+OK")[1], 16);
+        if (crc8 !== undefined && hash !== undefined)
+          connector.verify(crc8, hash);
+      }
     },
-    [t, connector]
+    [t, connector, crc8]
   );
 
   const writeCode = useCallback(async () => {
@@ -453,6 +462,14 @@ export const Home = () => {
                 compileStatus.status !== "success" || !connector.isWriteMode
               }
             />
+            <ControlButton
+              label={t("検証")}
+              icon={<Plagiarism />}
+              onClick={() => send("verify")}
+              disabled={
+                compileStatus.status !== "success" || !connector.isWriteMode
+              }
+            />
             <ControlButton
               label={t("実行")}
               icon={<FlagIcon />}
diff --git a/src/utils/crc8Calculator.ts b/src/utils/crc8Calculator.ts
new file mode 100644
index 0000000..89e4757
--- /dev/null
+++ b/src/utils/crc8Calculator.ts
@@ -0,0 +1,16 @@
+export const crc8Calculator = (data?: Uint8Array) => {
+  const hash = data?.reduce((crc, byte) => {
+    const poly = 0x31;
+    crc ^= byte;
+    for (let i = 0; i < 8; i++) {
+      if (crc & 0x80) {
+        crc = (crc << 1) ^ poly;
+      } else {
+        crc = crc << 1;
+      }
+    }
+    crc &= 0xff;
+    return crc;
+  }, 0xff);
+  return hash;
+};