An injection molding machine having in spaced positions at least a first injecting station for injecting a plasticized resin material into a die cavity and a second station for further treating the injected resin material concurrently and in relation with the injecting operation at the injecting station, the molding machine including a die carriage movable to and from the first and second stations and fixedly supporting thereon at least a lower die of an injection molding die set; a track for guiding movements of the die carriage to and from the respective stations; a carriage clamp for fixing the die carriage at the respective stations; a die closing mechanism provided at each station for releasably clamping an upper die against the lower die; and a drive mechanism for moving the die carriage sequentially to the first and second stations.