To surely detect a shift operation position of a shift lever without causing a problem of contact failure of a movable contact with fixed contacts.

A rotator 18 interlocking with an action transmitted from the shift lever for conducting a shift operation of the automatic transmission has the movable contact 24 consisting of a rolling body of a conductive material. Accompanying with an action of the rotator 18, the movable contact 24 selectively contacts with the fixed contacts 15... while rotating and thus it is free from a problem of wear debris generation which is caused by a conventional mechanism in which a movable contact contacts with a fixed contact while sliding. Thus, the problem of contact failure owing to wear debris of the movable contact 24 against the fixed contacts 15... is not caused and the shift operation position of the shift lever can be surely detected.