A switch is provided with a reset function including a heart cam portion which extends from a locked position to a side where a lock pin operation end biases, and a lock release passage IV which is blocked off by a lock pin retention protrusion during being retained. The lock pin retention protrusion is moved by biasing force of the lock pin operation end so that the locked state is released by opening the lock release passage IV. This embodiment can decrease wear between the lock pin and the member for retaining the lock pin.