PURPOSE: To perform molding of stable quality by controlling the heating temp. or closing speed of a mold corresponding to the change of a molding condition.

CONSTITUTION: A closing position sensor 4 detecting the closing speed of molds 1, 2, a mold inner pressure sensor 5 detecting the pressure in a cavity 3, a resin temp. sensor 6 detecting the temp. of the molding material in the cavity 3 and a mold temp. sensor 7 detecting the temp. of the molds 1, 2 are provided to the molds 1, 2. A control unit controlling the closing speed or heating temp. of the molds 1, 2 on the basis of the detected data due to the sensors 4, 5, 6, 7 is provided. When the pressure or temp. condition acting on the molding material in the cavity 3 changes, the change state is detected by the mold inner pressure sensor 5 or the resin temp. sensor 6 and the detected value is fed back by the closing position sensor 4 or the mold temp. sensor 7 to control the closing speed or heating temp. of the molds 1, 2.