The invention provides a steering wheel lock device for reliably preventing undesirable automatic recovery, comprising: a cylinder component (23) contained in a steering wheel lock body (10); a cam element (33) rotating together with the cylinder component; a lock bolt (47) which passes in and out to lock a steering shaft when the cam component is at a LOCK position, and draws back towards a releasing position when the cam component is at ACC position, ON position and START position on the other hard; and a switch component (ignition switch (55)) coupled and rotated with the cam component. A first cam surface (41) which extends from LOCK position to ACC position and makes the lock bolt act towards the withdrawing direction, a second cam surface (42) extending from ACC position to ON position of the cam component, and a third cam surface (43) extending from ON position to START position of the cam component are mounted on the cam component, characterized in that, semidiameter of the third cam surface (r3) is smaller than semidiameters (r1, r2) of the first and the second cam surfaces.