Key switch

A key switch includes a cam member rotating in accordance with the insertion-and-pull of a key to be inserted into a key insertion opening, a plunger coming into contact with a circumferential cam side of the cam member, a switch mechanism actuated by the plunger which is displaced in accordance with the rotation of the cam member, and a rotation lock mechanism for locking the rotation of the cam member when the key is pulled, in which the rotation lock mechanism including a locking member which can be displaced in the direction parallel to a vertical rotation face on the rotation axis of the cam member and a spring urging the locking member toward a position to be engaged with the cam member, and the locking member being disposed to be displaced to a lock release position by contacting the key resisting the spring.