To palletize in a fast speed, dispensing with an action to pull out a hand while aligning workpieces, in a palletizing device transferring the workpieces by grasping them with the hand with claws and aligning and stacking them onto a pallet.

This device includes the hand 2 grasping the workpiece W, and an arm 3 transferring the hand 2 so as to sequentially convey the workpiece W, and align and stack them onto the pallet 7. The hand 2 includes long claws 21 grasping the workpiece W, retractable claws 22, and a retraction mechanism retracting the retractable claws 22. The arm 3 transfers the hand 2, which grasps the work W with the use of the claws 21, 22, so as to transfer the workpiece W onto the pallet 7. The hand 2 retracts the retractable claw 22 on the front side in the direction x1 for aligning the workpiece W with the use of the retraction mechanism. The long claw 21 on the rear side in the above direction x1 pushes the workpiece W so as to align the workpiece W. The retractable claw 22 retracts during alignment, eliminating a need to pull out the hand 2.