To perform surely connection/disconnection of a contact and to speed up the connection/disconnection of the contact.

In this switch, a contact plate 13 is swingably supported by a contact plate supporting part 11 on a side of a housing 3. A movable contact 15 is provided on one side of the contact plate 13 bordered by the contact plate supporting part 11, and a recess 13b for acceleration for dropping in a steel ball 39 is provided on the other side of the contact plate 13. A movable board 23 is made up of a first movable board part 25 subjected to moving operations by a switch knob and a second movable board part 27 supporting the steel ball 39 and movably supported relative to the first movable part 25 in a predetermined range. By allowing the second movable board part 27 to move relative to the first movable board part 25, the steel ball 39 drops into the recess 13b to thereby cause swinging displacement of the contact plate 13 toward the side of the recess 13b instantaneously and to separate the movable contact 15 from a stationary contact 5 instantaneously.