To easily fix various fixing objects on a plaster board with driving stop material by penetrating reinforcing material by adhering reinforcing material composed of carbon fiber-based FRP on the surface of the plaster board in which holding by the driving stop material is difficult.

A decorative plywood-made hanging shelf 3 is adhered on a wall face surface composed of a plaster board 1 through a reinforcing material 2 forming a cyanoacrylate-based adhesive 22 on both the faces of a base component 21 composed of carbon fiber-based FRP, and the reinforcing material 2 is penetrated from the inside of the hanging shelf 3 to drive machine screws 4 into the plaster board 1 so as to fix the hanging shelf 3. The reinforcing material 2 may be adhered on the rear face of the plaster board 1 to penetrate the machine screws 4 into the rear face. In addition, a hole is drilled in the plaster board 1 to fill and solidify heated and molten ABS resin composition or room temperature hardening epoxy resin, and the machine screws 4 may be driven into a formed reinforcing part. Thereby the hanging shelf 3 can be fixed on the surface of the plaster board 1.