A keyboard has a base plate, a membrane sheet, a housing, a key-top, a link mechanism disposed between the housing and the key-top, and a switch operating member disposed under the key-top and operated by the key-top. The housing, the membrane sheet and the base plate have slits at a position corresponding to a surrounding portion of the key-top. Consequently, the distance between the key-top and the housing can be decreased even if the skirt part of the key-top is long. Furthermore, the slit of the housing is formed as a discontinuous annular shape to surround the link mechanism, and the surrounding portion of the key-top has a slit corresponding to the bridge shaped portion of the housing.