A portable electronic device includes a screen module, a main body module and an input/output module. The screen module is pivotally connected with the body module. The input/output module is electrically connected with the main body module. An actuating element is disposed at a bottom of the screen module. When the screen module is opened respectively to the body module to be opened, the actuating element is driven to swing to push a front end of the input/output module to be lifted to drive the input/output module to be out of a state that the keyboard abuts against the main body module. Therefore, the portable electronic device is easy to be operated. Moreover, the heat dissipation is improved to keep the internal temperature low and reduce energy consumption.