To obtain a hot press molding method improved as a stone material composite panel producing method reducing the cracking of a stone material at a time of the production of a panel and enhanced in productivity and workability by interposing a cushion material between a surface material and a press upper hot plate to subject the whole to hot press molding.

When a stone material 1 and a lining material 2 are laminated to be molded by a hot press, molding is performed in such a state that a cushion material 3 is interposed between the stone material 1 and a hot press. As the stone material used as the surface material 1, a natural stone material such as marble or granite and an aritificial stone material such as various ceramics or terrazzo are designated. As the natural stone material, a thin stone material being a standard product with a thickness of 3-17mm obtained by cutting a thick stone material slab by a band saw is pref. used. As the lining material, a material obtained by bonding a metal skin or an FRP skin on the surface of a base material composed of a honeycomb core made of a metal or resin, resin foam or lightweight foam such as inorg. foam is used.