PURPOSE: To prevent unnecessary operation of a carriage by providing a preventing part on a carriage spacing means and preventing it from moving by abutting a lower carriage in close-contact with one surface opposite to the other surface of a selected carriage.

CONSTITUTION: A change plate 43 is formed with a carriage lifter 140 having a cross section of an approximately round shape and a stopper 141 having a tip formed with a slant surface. The lifter 140 is brought into contact with a lower slant surface on a trianguler protrusion part of one carriage above a carriage to be drawn out, and hence the carriage in contact is moved upward. The stopper 141 is brought into contact with a protrusion part of one carriage 58 below the carriage 59 to be drawn out at the time of moving a carriage upward by the lifter 140 in abutting a protrusion part of this carriage. By this method, carriages other than the carriage to be drawn out are fixed not to be moved. Moreover, the carriages 58 and 59 are prevented from unnecessarily moving in a stocker by carriage stoppers 86 and 87 provided on a right side chassis part.