To provide a press bonding device using one differential pressure cylinder for increasing a machine tact (a working speed) without using a high speed actuator, separately.

The press bonding device comprises a high pressure side first pressure control circuit 20 including a first solenoid selector valve 22 having a pressure open side/pressure side change-over stage for connecting a pressure fluid source PS to a first cylinder chamber 10a, a low pressure side second pressure control circuit 30 including a second solenoid selector valve 32 having a pressure open side/pressure side change-over stage for connecting the pressure fluid source PS to a second cylinder chamber 10b, and a first sensor S1 for detecting a piston 11 at an original position and a second sensor S2 for detecting the piston 11 at an intermediate position apart from the original position. The piston 11 is smoothly moved between the original position and the intermediate position with the first solenoid selector valve 22 on a pressure side stage 22a and the second solenoid selector valve 32 on a pressure open side stage 32a. On or past the intermediate position, it is put into a differential pressure operated condition with the first and second solenoid selector valves 22, 32 on the pressure side stages 22a, 32b, respectively.