To prevent a movable contact from having a defect in switching even when a cam disk is rotated fast.

A changeover switch has a cam disk 18 having a recessed cam 181 at an outer periphery, a pair of stationary contacts 12, 13, and a movable contact 16 which has a pair of contact parts 161, 162 capable of contacting and leaving both the stationary contacts 12, 13 and also has a cam follower 19 engaging the recessed cam 181. The recessed cam 181 acts as the cam disk 18 rotates so that the movable contact 16 is switched through the cam follower 19 from a state of contacting of one contact part 161, 162 with one stationary contact 12, 13 to a state of contacting of the other contact part 161, 162 with the other stationary contact 12, 13. The cam disk 18 and movable contact 16 are provided with an auxiliary operation mechanism 20 which places the movable contact 16 in switching operation when the movable contact 16 has a defect in switching between the recessed cam 181 and cam follower 19.