To form a molded body easily made of a transparent synthetic resin and a colored synthetic resin or two differently-colored synthetic resins.

This injection molding machine is equipped with a cylinder 2 having an injection hole 2a at the head, a torpedo arranged within the cylinder 2, a plunger 3 which reciprocates in the cylinder 2, a heater 4 provided at the perimetrical surface of the cylinder 2, and feeders 5a, 5b which supplies synthetic resins in the cylinder 2, and a through hole is provided in the torpedo, a bar head 3a which reciprocates in the through hole of the torpedo in association with the reciprocal motion of the plunger 3 is provided.