A switch has a base comprising a flat circular recess formed on an upper surface thereof, a fixed contact disposed in an inner surface of the flat circular recess, a spring body that has a bellows shape in which a reference form unit is repetitively formed, the spring body being annularly disposed in the flat circular recess of the base, an operating body that has a turning unit fitted turnably in the flat circular recess of the base, and an operating projection provided in an inward surface of the turning unit. When the operating body is turned, the operating projection presses an end portion of the spring body to compress the spring body, which allows a contact to be switched.