A portable electronic device includes a first component, a second component, a pivoting device, a cover member and a linkage module. The second component is pivotally coupled to the first component through a pivoting device. The second component has an internal space and a sunken portion. The sunken portion is in communication with the internal space. The cover member is movably embedded in the sunken portion. The linkage module is coupled to the pivoting device and the cover member for selectively pushing the cover member out of the sunken portion with the movement of the pivoting device.