An electronic device includes a casing, a supporting member, a sliding lid and an elastic member. The casing has a window. The supporting member is in the casing and has a through hole. The sliding lid is slidably disposed on the supporting member so that the sliding lid is slidable between an opened position and a closed position. The through hole is connected to the window when the sliding lid is located at the opened position, and the sliding lid is located between the through hole and the window when the sliding lid is located at the closed position. The elastic member is located on the same side of the sliding lid and the supporting member. One end of the elastic member is disposed on the sliding lid, and another end of the elastic member is disposed on the supporting member.