To provide an exterior material that can be used as an interior wall material, an exterior wall material, a roofing material, a ceiling material, a flooring material, a partition material, a fire door and, etc., and is excellent in fire-preventiveness, fireproofness and mechanical strength while being free from deformations such as swelling or warping liable to occur after manufacture.

A metal surface material 1 is composed of projecting pieces 5 made up by projecting outward both ends of a fancy surface 2, indented linear grooves 6 formed at the projecting pieces 5, waterproof pieces 7 formed by bending the front ends of the linear grooves 6 outward, waterproof flanges 8 made up by turning the front ends of the waterproof pieces 7 inwardly, and holding pieces 9 formed at both ends of the fancy surface 2. An exterior material is formed by sandwiching a core material 11 made of plastic foam 12 and incombustible boards 13 formed at both ends thereof between the metal surface material 1 and a reverse side material 14 composed of a horizontal planelike reverse fancy surface 15 and reinforcing pieces 16 made up by bending both ends of the reverse fancy surface 15 inwardly.