PURPOSE: To obtain a high-quality molded article which can be molded without having a time loss even to a different kind of resin having a difference in a heat deformation temperature, by a method wherein molding is performed by controlling respectively and independently the temperature of a primary molding part of a cavity plate and that of a secondary molding part of the cavity plate.

CONSTITUTION: The titled injection molding method is so constituted that a heating medium is streamed to a heating medium circulation pipe 11a which is being laid in a primary molding part 2a of a cavity side 2 and the primary molding part 2a of the cavity plate 2 become the temperature through which hard resin is curable in the vicinity of the softening point of the hard resin. This is for the sake of setting a hard resin so that an appearance becomes favorable without having a sink. The titled method is so constituted that a heating medium is streamed to a heating medium circulation pipe 11b which is being laid in a secondary molding part 2b of the cavity plate 2 prior to a secondary molding and the secondary molding part 2b of the cavity plate 2 becomes the temperature through which soft resin is setable in the vicinity of the softening point. This is for the sake of setting the soft resin without generating a defect such as burrs. With this construction, even a different kind of resin having a difference in a heat deformation temperature can be manufactured without having a time loss and a high-quality molded article can be obtained.