An electronic device includes a frame defining a slot and a through hole, a slot cover moveably received in the slot, an elastic piece rotatably connected to the frame, and a torsion spring. The elastic piece includes a main body, a side arm and an extended tab defined on opposite ends of the main body. When the elastic piece is at a normal position, the side arm faces the first through hole, and the tab faces the slot. The torsion spring includes a first arm fixed to the frame and a second arm fixed to the elastic piece. The elastic piece is rotatable by insertion of an elongated object into through the through hole to push the side arm, thereby causing the tab to push the slot cover to be deformed until the hook disengages from the slot.