To securely prevent a carrier from departing from the end of a movable side rail on the way to deliver the carrier.

Fixed side rails 1, 2 and the movable side rail 4 are disposed so as to have a predetermined distance S between them. The device is equipped with a position restriction mechanism 16 forcibly restricting vertical and horizontal positions relative to the fixed side rails 1, 3 of the movable rail 4 moved near the fixed side rails 1, 3 by a moving means to a predetermined position, a carrier drop prevention member 17 preventing the carrier 2 guided with a special fixed side rail 1 from departing from the side end of the movable side rail of the fixed side rail 1, and a movable side carrier drop prevention member 18 preventing the carrier 2 delivered to the movable side rail 4 from departing from the side end of the fixed side rail.