PURPOSE: To prevent the damage of a work through prevention of the occurrence of interference between a pull-down claw and an obstacle, to make the forced lowering position of a work unchanged, and to bring teaching position data into an unusable state as it is, by a method wherein a stopper is moved according to the size of the work.

CONSTITUTION: In a hand device, during conveyance of a large work, a work 7 is conveyed in a regulated state in a position in which a stopper 9 is moved backwardmost, and in which case, the work is protruded from a tip part 3a of a pull-down claw 3. The work 7 is placed in a manner described above on a pallet 10. Meanwhile, during conveyance of a small work 7a, the stopper 9 is moved forward and the work 7a is regulated to a position in which the work is protruded from the tip part 3a of the pull-down claw 3, and the work is placed on the pallet 10. This constitution causes the hand device to prevent the tip part 3a of the claw 3 from interference with an obstacle 11, e.g. a wall, during movement of the work to the pallet 10 irrespective of the size of the work 7.