To save a space, shorten the process cycle time, and facilitate the control by placing a raw material from a raw material pallet onto a working pallet, and placing a product from the working pallet carried out of a plate material working machine onto a product pallet.

Height of a product traverser is set at a height capable of smoothy receiving a product pallet 20 moved from a product pallet housing unit 21 inside of a work stock unit 3 by a product pallet traverser 22 onto a table surface 41. Working pallet carry-in/out height is set at a height capable of smoothly receiving a working pallet 30 carried out of a laser working machine 2 by the working pallet traverser 32 onto the table surface 41. Since the raw material pallet housing unit and the product pallet housing unit are arranged in parallel with each other in the vertical direction, space can be saved, and since both the pallets can be vertically moved by the only one lifter table, the process cycle time can be shortened, and since the only one lifter table is used, control is facilitated.