A switch apparatus has a case that includes a hollow projecting support section, a switch contact provided inside the case, and a button having a depressing section that comes into contact with the switch contact and mounted on the support section in a manner vertically movable. Furthermore, an inwardly projecting catch section is provided on the inner periphery of the support section, and an engaging hole is provided on the depressing section of the button into which the catch section is to be inserted. In this configuration, an opening on the top surface of the case is not required when manufacturing the case and the button by resin molding. As a result, a switch apparatus is obtained which is superior in resistance to water and dust and stable in operation.