To automate work for separating plywood 5 from a combination body 2 wherein the plywood 5 that is a protective member is lapped on a pallet 4, placing an object 7 such as a cardboard sheet onto the pallet 4, and placing the plywood 5 onto the object 7.

In this stacking device, the combination body 2 wherein the pallet 4 and the plywood 5 are overlapped is fed from a first feeding means 3 one by one, and is carried by a second carrying means 11. A detection means 6 detecting the presence of the plywood 5 on the pallet 4 is provided halfway along a carrying route 12 of the second carrying means 11. When the the detection means 6 detects the single sheet of plywood 5, a robot 9 separates the plywood 5 and temporally lays the plywood 5 onto a temporally-laying area 71 in a work area 69. Next, the object 7 from a second feeding means 8 is grasped and placed onto the pallet 4. Next, the robot 9 places the plywood 5 from the temporally-laying area 71 onto the object 7. Finally, the pallet 4, the object 7 and the plywood 5 are bound and packed by a belt 15, and are made to be a shipment packing style.