PURPOSE: To simplify the execution and reduce the cost by forming a vertically long rectangular frame, having intermediate frames, with shape steel to be linked between upper and lower story slabs and mounting a sheathing panel directly on the frame.

CONSTITUTION: A vertically long rectangular frame 2, having intermediate frames 6, is formed of shape steel and mounted between upper and lower story slabs A, A through fasteners 11. Next, a sheathing panel single unit 3, provided with groove-shaped mounting parts 7, is fixed to the frame 2, and a junction part between the panel single units 3 is filled with a seal material to apply water stop treatment. In this way, the execution can be simplified.