PURPOSE: To obtain a thin molding like loudspeaker cone by a method wherein a metallic mold having preferable shape of face is heated to a given temperature, a powder resin is applied evenly on the face to fuse and mold into a product of desired thickness, and then the mold is released after cooling.

CONSTITUTION: A metallic mold 2 with a face 1 shaped in a product to mold, a loudspeaker cone for example, formed on one side is heated to 330W340°C, and a given quantity of a powder resin 11, nylon for example, is applied 3 evenly on the face 1 through spraying or fluidized dipping, which is fused to form a product A of a desired thickness 0.1W2.0mm for example. Then, it is cooled down and hardened, released from the face, thus obtaining a thin molding of synthetic resin. where a thick molding is necessary, cold press is further applied thereon.