To smoothly stack member without the member being decayed by resilience even if a box in a state in which a center is expanded is pushed out by arranging a sheet for covering a top face of a stepped load member fed out to a third carrying unit and mounting both ends thereof to an extruding unit.

When a first stacking member 1' is loaded on a third carrying unit 4, a sensor 8 detects it, and the stacking member 1' is sequentially pushed out by a cylinder 6. Since a sheet 13 pressurizes the top face of the stepped load member 1' by a predetermined pressure, even a box shaped member whose center is expanded is never decayed. When the stacking member 1' is loaded on the third carrying unit 4 in predetermined quantity, a pressure plate 11 of an extruding unit 10 presses and holds the top face of the stacking member 1' by means of a cylinder 12 in which state the plate is extruded horizontally and housed in an integrating box 18. Then, the pressure plate 11 returns to its original position. This operation is returned, and the stacking member 1' is integrated in the integrating box 18.