PURPOSE: To improve the reliability of positioning work by providing a positioning mechanism of pallet, a conforming mechanism to conform the up and down position of the uppermost pallet and the up and down position of the positioning mechanism, and control mechanism connected to both mechanism.

CONSTITUTION: A positioning mechanism 50 is composed of a driving member 51 and a stopper 52 provided opposing to the driving member 51. The driving member 51 is composed of the plunger of a fluid pressure cylinder to press a pallet C toward the stopper 52. The conforming mechanism 60 is composed of a lifter to hold the pallet group loaded in multistage. The positioning mechanism 50 and the conforming mechanism 60 are connected to a control mechanism. The control mechanism conforms the up and down position of the uppermost pallet C and the up and down position of the positioning mechanism 50 by operating the conforming mechanism 60, and positions the horizontal position of the uppermost pallet C to a specific position by operating the positioning mechanism 50. Consequently, the reliability of the positioning work can be improved.