Abstract: An apparatus including a treating container having at its inner lower portion a space for containing a charge of synthetic resin powder. An agitator is provided therein having an agitation blade means for spattering upwards the charged layer of synthetic resin powder. A metallic mold is provided thereabove closing an upper surface of the treating container. The metallic mold is provided with a downwardly directed molding mold surface for facing the charged powder layer. The mold surface thereof is arranged to be selectively heated or cooled at will. This invention is characterized in that a rotary frame is provided on one side of the treating container, at least two of the metallic molds are so disposed on the rotary frame as to be at rotationally symmetrical positions, and the treating container is so arranged as to be retreated outside the rotation loci of these metallic molds.