To form a component mounting portion having high strength and durability on the wall surface of a backing plaster board in a short time.

Before mounting a hook 5 on the wall face of the plaster board 2 as a backing material, a through-hole 3 is first formed in the plaster board 2 and then an adhesive 7 is applied to an inner peripheral face 3b thereof. Without waiting for the hardening of the adhesive 7, an anchor member 4 is immediately screwed into the through-hole 3 and fixed thereto and a machine screw 6 of the hook 5 is screwed into a tapped hole 44 of the anchor member 4, whereby the mounting of the hook 5 is completed in a short time. Before the adhesive is hardened, a load on the hook 5 is supported by the mechanical engaging force of the anchor member 4, and after it is hardened, the supporting strength of the hook 5 and the durability of the hook mounting portion are both further improved than conventional by the synergic effects of the mechanical engaging force and the adhesive force of the adhesive and the strength of the inner peripheral face 3a of the through-hole in the plaster board 2, which is increased by the hardening of the impregnated adhesive.