To prevent the occurrence of delustering and color fading over a long time even when exposed to the sunlight by improving weatherability of a gel coat layer, particularly, ultraviolet ray resistant strength when decorating a surface of a decorative building material molded by a fiber reinforced resin with the gel coat layer.

This decorative building material 1 for an outer wall is constructed by an inorganic wallboard 2. An outside surface of a body 4 composed of the fiber reinforced resin is colored with the coloring gel coat layer 5, and an outside surface of the coloring gel coat layer 5 is coated on the top with clear paint 6 by adding an ultraviolet ray absorber.