Abstract: In a molding machine, a fixed platen which supports a fixed die is disposed on one end of a base plate. A movable platen which supports a movable die and a supporting mount which supports each one end portion of the four tie bars are mounted on slide units. The movable platen and the supporting mount are advanced so as to close the die, a tip portion of each tie bar is locked to the fixed platen by a lock mechanism, and a die clamping cylinder provided on the movable platen is actuated to generate a clamping force so as to execute molding. After that, the lock mechanism executes an unlocking operation so as to cause the movable platen and the supporting mount to retreat to a die open position. Furthermore, an attaching and detaching mechanism releases the die clamping cylinder so as to cause only the supporting mount to significantly retreat from the movable platen, and thus the four tie bars are completely evacuated from the fixed die and the movable die.