PURPOSE: To constitute a push-button switch on an insulation base which have the same structure when a dome-form contact is used for a movable contact as when a conductive rubber is used.

CONSTITUTION: A first fixed contact 12 is arranged in an exposed state at the central part of the bottom of a recessed hole 11 formed in an insulation base 10, and a second fixed contact 13 comprising a first exposure part 13A arranged in an exposed state in a position in the vicinity of the first fixed contact and a second exposure part 13B arranged in an exposed state to the peripheral edge of the recessed hole is provided to form an insulation base 10. When a dome-form contact is used, continuity is made between the second exposure part 13B and the first fixed contact 12 and when a conductive rubber is used, continuity is made between the first fixed contact and the first exposure part.