A printed wiring board has a first switch contact pattern, a second switch contact pattern, and a cutting portion that cuts a plating bar formed thereon. A metal dome is arranged to be in contact with the first switch contact pattern and allows the first switch contact pattern and the second switch contact pattern to be conductive by being deformed. A first sheet attached to the printed wiring board via an adhesive has a first opening portion formed in a region where the metal dome is arranged and a second opening portion formed in the region where a cutting portion is formed. A second sheet is attached to the first sheet via the adhesive to cover the first opening portion and the second opening portion.