PURPOSE: To produce a heat insulating and sound insulating effect by mounting a plaster plate, in the surface of which a recessed holes are formed by embossing, on a wall backing, fixing a decorative plate through a double-coated adhesive tape, and creating synergism of a space formed with a number of holes and gaps.

CONSTITUTION: A plaster plate 5 is mounted on the whole surface of a backing 3 made of wood of a wall 1 in a manner that vertical joints 8 are displaced from each other. The plaster plate 5 is mounted on the backing 3 in a state that rectangular holes 4 formed in a meandering manner in the whole of the surface of the plaster plate 5 are front, and a decorative plate 7 is fixed through a double-coated adhesive tape 6 mounted in a given spot. As noted above, a gap equivalent to the thickness of the double-coated adhesive tape 6 is formed between the plaster plate 5 having a number of holes formed in the whole of a surface and the decorative plate 7 fixed through the double-coated adhesive tape 6. This constitution produces a heat insulating and sound insulating effect by synergism of a space and eliminates an ordinary furring strip.