An electronic apparatus including a main body and a detachable input device is provided. The main body has a first connecting interface. The detachable input device has an input interface and a second connecting interface. When the detachable input device is installed on the main body, the first connecting interface contacts the second connecting interface, and the detachable input device transmits signals to the main body through the first connecting interface and the second connecting interface, and receives electric power from the main body through the first connecting interface and the second connecting interface. When the detachable input device is detached from the main body, the first connecting interface is separate from the second connecting interface, and the detachable input device transmits signals to the main body in a wireless manner.