A switch device includes a substrate provided with at least one first contact and including at least one through hole, and a contact rubber, being an elastic sheet covering the substrate, provided with a dome-shaped cavity configured to make a second contact portion including a second contact corresponding to the first contact elastically deformable to be capable of contacting to and separating from the first contact, a vent cavity portion provided corresponding to the through hole, and an air groove communicating with the cavity and the vent cavity portion between the substrate and the elastic sheet. The through hole is an independent through hole being not electrically connected to a circuit of the substrate.