An injection molding machine (10, 30) for two-material molding comprising: a base, a movable die plate to which a movable side mold is attached, the movable die plate being movably mounted on the base, a fixed die plate to which a fixed side mold is attached, the fixed die plate being fixedly provided at the end of the base, a reversal pedestal that is provided between the movable die plate and the fixed die plate and movable in a same direction as the movable die plate; a rotational die plate that is 180 degrees rotatable on the reversal pedestal and to which molds are attached on both sides thereof to fit with the movable side mold and the fixed side mold and define respective cavities; a movable die plate mold opening and closing unit (14; 46)that opens and closes the mold of the movable die plate; a rotational die plate mold opening and closing unit that opens and closes the molds of the rotational die plate; a mold clamping unit that mold-clamps the three sets of die plates simultaneously after mold closing; and two sets of injection units (11, 12) that plasticize different resin materials and injection-fill the materials, wherein the mold clamping unit is a hydraulic mold clamping unit that mold-clamps the three sets of die plates simultaneously, the movable die plate opening and closing unit (14; 46) is a movable die plate opening and closing unit (14; 46) driven by an electric motor, the rotational die plate opening and closing unit is a rotational die plate opening and closing unit driven by an electric motor, and a rotating unit (16; 50; 60)for the rotational die plate is a rotation driving unit driven by an electric motor attached to the reversal pedestal, characterized in that one set out of the two sets of injection units (11, 12) is provided on the fixed die plate side and forwardly and backwardly movably with respect to the fixed die plate, another set (11, 12) is provided on a slidable base, the slidable base being fixed on the movable die plate with a connecting and fixing member interposed there-between, the another set (11, 12) being movable forwardly and backwardly with respect to the movable die plate, in mold opening and closing of the movable die plate, the other set of injection units (11, 12) is movable by a nozzle touch cylinder while abutting to the mold attached to the movable die plate, the nozzle touch cylinder enabling the other injection unit (11, 12) to slide on the slidable base. a base, a movable die plate to which a movable side mold is attached, the movable die plate being movably mounted on the base, a fixed die plate to which a fixed side mold is attached, the fixed die plate being fixedly provided at the end of the base, a reversal pedestal that is provided between the movable die plate and the fixed die plate and movable in a same direction as the movable die plate; a rotational die plate that is 180 degrees rotatable on the reversal pedestal and to which molds are attached on both sides thereof to fit with the movable side mold and the fixed side mold and define respective cavities; a movable die plate mold opening and closing unit (14; 46)that opens and closes the mold of the movable die plate; a rotational die plate mold opening and closing unit that opens and closes the molds of the rotational die plate; a mold clamping unit that mold-clamps the three sets of die plates simultaneously after mold closing; and two sets of injection units (11, 12) that plasticize different resin materials and injection-fill the materials, wherein the mold clamping unit is a hydraulic mold clamping unit that mold-clamps the three sets of die plates simultaneously, the movable die plate opening and closing unit (14; 46) is a movable die plate opening and closing unit (14; 46) driven by an electric motor, the rotational die plate opening and closing unit is a rotational die plate opening and closing unit driven by an electric motor, and a rotating unit (16; 50; 60)for the rotational die plate is a rotation driving unit driven by an electric motor attached to the reversal pedestal, characterized in that one set out of the two sets of injection units (11, 12) is provided on the fixed die plate side and forwardly and backwardly movably with respect to the fixed die plate, another set (11, 12) is provided on a slidable base, the slidable base being fixed on the movable die plate with a connecting and fixing member interposed there-between, the another set (11, 12) being movable forwardly and backwardly with respect to the movable die plate, in mold opening and closing of the movable die plate, the other set of injection units (11, 12) is movable by a nozzle touch cylinder while abutting to the mold attached to the movable die plate, the nozzle touch cylinder enabling the other injection unit (11, 12) to slide on the slidable base.