A control apparatus of a press machine in which a motor performance torque is fluctuated in accordance with a rotational angle of the rotating body in the case of rotating the motor at a fixed instruction speed. The IGBT has an auxiliary base layer which is formed in an arbitrary region between two adjacent trenches and is insulated from an emitter electrode of the IGBT, and a carrier discharge electrode which contacts a surface of the auxiliary base layer. A diameter of the translucent inner envelope is smaller than a diameter of the translucent outer envelope. Upon the cores being formed, the center plate holding the cores, is lifted and rotated to a juxtaposed position against a stripping plate, whereby the cores are mechanically separated from both the mold and overflow flashing.