diff --git a/README.md b/README.md
index fd9b8bcc..ec64efaf 100644
--- a/README.md
+++ b/README.md
@@ -57,39 +57,8 @@ Or you can set proxy by following command line options.
 * `--proxy-server=<SERVER>:<PORT>`
 * `--proxy-pac-url=<URL>`
 
-
-## Testing and Development
-Node.js is required to test this app.
-
-### Simple testing
-1. Clone or download the source code.
-2. Run `npm install`.
-3. Run `npm start`.
-
-When you edit `src/**` files, please execute `npm run build` before `npm start`.
-
-### Development
-###### `npm run watch`
-Reload the app automatically when you have saved source codes.
-
-###### `npm test`
-Run tests with Mocha.
-
-## Packaging
-You can package this app with following commands. Packages will be created in `release` directory.
-
-```
-$ npm run package (for your platform)
-$ npm run package:windows (Requires Windows or Wine)
-$ npm run package:osx (Requires OS X or Linux)
-$ npm run package:linux
-$ npm run package:all (Packages for all platform)
-```
-
-Create a windows installer with the following command. It will appear in the `release\windows-installer` directory.
-```
-$ npm run installer
-```
-
 ## Contributing
 Please see [CONTRIBUTING.md](./CONTRIBUTING.md).
+
+## Development
+Please see [docs/development.md](./docs/development.md).
diff --git a/docs/development.md b/docs/development.md
new file mode 100644
index 00000000..50fe2994
--- /dev/null
+++ b/docs/development.md
@@ -0,0 +1,99 @@
+# Mattermost Desktop Development Guides
+
+## Build instructions
+
+### Prerequisites
+- C++ environment which supports C++11 (e.g. VS 2015, Xcode, GCC)
+- Python 2.7
+- Node.js 4.2.0 or later
+- Git
+
+### Installing dependencies
+`npm install` is executed twice to install dependencies of `src/` directory.
+
+```
+$ npm install
+```
+
+### Building
+Build JavaScript codes with `webpack`, and copy other assets into `dist/` directory.
+
+```
+$ npm run build
+```
+
+After building is done, you can execute the application with `npm start`.
+
+### Tests
+Execute automated tests.
+
+```
+$ npm test
+```
+
+There are two steps in `npm test`.
+
+Test functionality:
+
+```
+$ npm run test:app
+```
+
+Test coding style:
+
+```
+$ npm run test:code
+```
+
+### Helper commmands
+
+#### `npm run watch`
+Reload the application automatically when you have saved source codes.
+
+#### `mpm run prettify`
+Format the source codes to pass `npm test`.
+
+#### `npm run package`
+You can package this application with following commands. Packages will be created in `release/` directory.
+
+```
+$ npm run package (for your platform)
+$ npm run package:windows (Requires Windows or Wine)
+$ npm run package:osx (Requires macOS or Linux)
+$ npm run package:linux
+$ npm run package:all (Packages for all platform)
+```
+
+Create a windows installer with the following command. It will appear in the `release\windows-installer` directory.
+
+```
+$ npm run installer
+```
+
+## Directory Structure
+
+```
+Mattermost Desktop
+├── docs/ - Documentations.
+├── resources/ - Resources which are used outside of the application codes.
+├── scripts/ - Helper scripts.
+├── src/ - Application source code.
+│   ├── browser/ - Implemtation of Electron's renderer process.
+│   │   ├── components/ - React.js components.
+│   │   ├── css/ - Stylesheets.
+│   │   ├── js/ - Helper JavaScript modules.
+│   │   └── webview/ - Injection code for Electron's <webview> tag.
+│   ├── common/ - Common JavaScript modules for both Electron's processes.
+│   ├── main/ - Implemtation of Electron's main process.
+│   │   └── menus/ - Application menu.
+│   └── resources/ - Resources which are loaded from the application codes.
+└── test/ - Automated tests.
+    ├── modules/ - Scripts which are commonly used in tests.
+    └── specs/ - Test scripts.
+```
+
+### Other directories
+- **dist/** - Built application code and asset.
+- **node_modules/** - Third party Node.js modules to build the application.
+- **release/** - Packaged distributable applications.
+- **src/node_modules/** - Third party Node.js modules to use in the application.