Abstract: An injection molding machine comprises an injection mechanism for heating and melting molding material and for injecting the molten material into cavities defined by a fixed die and a movable die and a die clamping mechanism for clamping and separating the fixed die and movable die. The fixed die is attached to a fixed platen provided near the injection mechanism and the movable die is attached to a movable platen provided near the die clamping mechanism. The die clamping mechanism is movable in a horizontal direction. A slider is provided on said movable platen and can reciprocably slide in a horizontal direction different from the direction in which the die clamping mechanism moves, and the aforesaid movable die and another movable die are attached to the slider so as to alternately come into face-to-face relation with the fixed die as the slider reciprocates.