To increase the advancing/retracting speed of a ram of a press cylinder under a no-load condition.

A ram 22 of the press cylinder 20 is connected to a rod 36 of an auxiliary cylinder 30 of small diameter. The ram 22 of the press cylinder 20 is advanced/retracted at a high speed by the auxiliary cylinder 30 when the press cylinder 20 is in a no-load condition. When the ram 22 is advanced at a high speed, a pre-fill valve 84 is opened to allow the working fluid to flow into a chamber 26 of the press cylinder 20 from a tank 88. When the ram 22 of the press cylinder 20 is in a pressing operation, the pressure in the chamber of the auxiliary cylinder 30 is increased, a switching valve 94 of a press pressure feed circuit 90 is operated to allow the chamber 26 of the press cylinder 20 to communicate with a chamber 40 of the auxiliary cylinder 30, the high-pressure working fluid is fed into the chamber 26 of the press cylinder 20 to pressurize in a large thrust at a low speed.