diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..75b7504
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,59 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+jobs:
+  frontend:
+    name: Frontend (tsc + vite build)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Build frontend
+        run: npm run build
+
+  rust:
+    name: Rust (cargo check — ${{ matrix.platform }})
+    strategy:
+      fail-fast: false
+      matrix:
+        platform:
+          - windows-latest
+          - macos-latest
+    runs-on: ${{ matrix.platform }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+
+      - uses: dtolnay/rust-toolchain@stable
+
+      - uses: swatinem/rust-cache@v2
+        with:
+          workspaces: src-tauri
+
+      - name: Install dependencies
+        run: npm ci
+
+      # tauri::generate_context! がコンパイル時に frontendDist (../dist) を要求するため、
+      # cargo check の前にフロントエンドをビルドしておく
+      - name: Build frontend
+        run: npm run build
+
+      - name: Check Rust backend
+        run: cargo check --manifest-path src-tauri/Cargo.toml