PURPOSE: To prevent a pump from discharging operating oil uselessly by comparing the detected operating speed of a hydraulic actuation device and the memorized preset speed, and outputting control signals to a motor controller and a control valve according to the comparison result.

CONSTITUTION: When the stroke speeds of piston rods 32a, 34a are lower than the preset speeds, the partition pressure of reducing valves 24, 26 is increased to increase the supply oil pressure to cylinders 32, 34, whereby the stroke speeds of the piston rods 32a, 34a can be increased. On the contrary, when the stroke speed is higher than the preset speed, the partition pressure of the reducing valves 24, 26 is lowered to decrease the stroke speed. Further, as a pump 12 is controlled in such a manner as to deliver operating oil a little more than the stroke speeds of the cylinders 32, 34, the pump 12 can be prevented from discharging a large quantity of operating oil uselessly so as to decrease the consumption energy.