PURPOSE: To make all the surfaces of ornamental materials even easily without limit to construction procedures by fixing a stopping plate at an anchor nut fixed in an outer wall surface, engaging a mortise of a heavy-weight ornamental material with the stopping plate, and filling mortar in a gap between the outer wall surface and the ornamental material.

CONSTITUTION: Anchor nuts 15 are provided and fixed at a predetermined interval in a wall body 14. A bolt 19 of a stopping plate 17 is then engaged with the anchor nut 15 to install the stopping plate 17 at the nut 15. The stopping plate 17 is then engaged in a mortise 11 in a lower side 13 of a heavy- weight ornamental material 5, and the stopping plate 17 is engaged in the mortise 11 in an upper side 12 of the ornamental material 5. The bolts 19 are thus engaged in order while adjusting their lengths to make the surface of the ornamental material 5 even. Mortar is then placed between the ornamental material 5 and the wall body 14 and hardened.