A switch includes a first arm that is rotatably supported, a first contact member that is provided at a free end of the first arm, a second arm that is rotatably supported, and a second contact member that is provided at a free end of the second arm and is to come into contact with the first contact member. After the first contact member and the second contact member have come into contact with each other, a point of contact between the first contact member and the second contact member is displaced with rotational motions of the first arm and the second arm.