To provide a switch device that can prevent the occurrence of problems of battery exhaustion, contact part corrosion and others.

In an ignition switch (switch device) which has a plurality of movable contacts 13-15 movable with an operating member and a plurality of stationary contacts (OFF terminal 7, ON terminal 8, ACC terminal 9 and ST terminal 10), including a power terminal (B terminal), arranged in insulated fashion and which switches conduction between the B terminal 6 and the other stationary terminals 7-10 by contact of the movable contacts 13-15 with the stationary contacts 6-10 when the operating member is operated, an operation stop position where the movable contacts 13-15 are not in contact with any of the stationary contacts 7-10 including the B terminal 6 is an OFF position.