A keyboard includes a base plate, a switch circuit board, plural swinging-type key structures, a light-emitting element, a light guide plate and a covering member. The light-emitting element emits a light beam. The plural swinging-type key structures are disposed on the switch circuit board. When one of the swinging-type key structures is pressed, the switch circuit board is triggered to generate a key signal. The light guide plate comprises plural light guide sub-plates. The light guide sub-plates are disposed on the corresponding swinging-type key structures. The covering member covers the base plate and the light guide plate. The covering member has a light-transmissible region. The light beam from the light-emitting element passes through the light-transmissible region. Consequently, the key structure is illuminated.