A portable electronic apparatus whose keyboard and display are switchable is provided. The apparatus comprises a main part and a detachable part that can be assembled to the main part. The main part includes a first display, a keyboard interface, and a display interface. One face of the detachable part is a keyboard, and an opposite face of the detachable part is a second display. The detachable part includes a display plug and a keyboard plug. When the keyboard plug of the detachable part is plugged into the keyboard interface of the main part the keyboard is enable to use. When the display plug of the detachable part is plugged into the display interface of the main part, the second display is enabled to use.