PURPOSE: To allow the lock and unlock of a key with a simple structure by forcedly rotating and returning a select lever to parking position, when the operating element of a key block is rotated to OFF position, by the engagement between the operating element and a hollow part one side surface.

CONSTITUTION: When an operating element 33 is in OFF position and a select lever 3 is in a shift position of parking 'P', the operating element 33 is within a rotating angle θ2, and the operating element 33 is also in contact with one side wall surface 3c of a rotating part 3a. A key 27 is inserted into a key through hole 25 and rotated within a rotating angle θ1, whereby the operating element 33 is laid in ON position to allow an engine to start. When the pulling operation of the key 27 is tried without shifting the select lever 3 to the parking 'P' position after stopping a vehicle, the operating element 33 pushes and moves the one-side wall surface 3c of the rotating part 3a counterclockwise in accordance with the counterclockwise orating operation of the key 27, and the rotating part 3a of the select lever 3 is forcedly rotated to the parking 'P' position.