An electronic device is provided. The electronic device includes a case, a mainboard, a cover and a locking module. The mainboard is disposed in the case. The cover covers the case. The locking module is disposed on the cover. The locking module includes a base, a latch, and a rotational member. The base is affixed to the cover. The latch is connected to the base, wherein the latch is moved between the first latch position and the second latch position relative to the base. The latch includes a recess and a protrusion. The rotational member is connected to the base. The rotational member is moved between the first rotational member position and the second rotational member position relative to the base. The rotational member includes a end portion, and the end portion is detachably connected to the recess. The locking module provides an automatic locking function.