Injection molding method and injection molding machine

An injection molding method and an injection molding machine are provided. The method uses the injection molding machine for two-material molding (10). The injection molding machine comprises a first mold part (1B) that is provided with a cavity (C2) and a second mold part (1A) that is provided with a cavity (C1) and is arranged in tandem with the first mold part (1B). This injection molding method comprises: a first molding step in which a material (P2) is injected into the cavity (C2) of the first mold part (1B) and the material (P2) in the cavity (C2) is compressed; and a second molding step in which a material (P1) is injected into the cavity (C1) of the second mold part (1A). By having the pressure to the second mold part (1A), the pressure being generated by injecting the material (P1) into the cavity (C1) in the second molding step, act on the first mold part (1B), a compressive force is applied to the material (P2) in the cavity (C2) in the first molding step. 本发明提供种注射成型方法、注射成型机。该注射成型方法利用双材成型用注射成型机(10