PURPOSE: To perform the release of a parking brake positively even in the case of the release of release operating force being performed a little earlier so as to improve operability.

CONSTITUTION: When a release cable 19 is pulled to rotate a release collar 15 into a lock release position and thereby to release the lock of pedal lock mechanism 13, a locking protrusion 25 on the peripheral side of the release collar 15 passes through the tip of a release collar locking lever 26 so as to be locked to the tip, thus constraining the release collar 15 in the lock release position. When a pedal lever 3 is reset into the initial position, the rear end of the release collar locking lever 26 is sprung up by a lever operating part 29 so as to release the engagement with the locking protrusion 25.