To obtain an electronic controlled pneumatic hydraulic pressure generator which reduces the difference between generated and desired hydraulic pressures by detecting constantly a compressed air pressure applied to the pneumatic hydraulic pressure generator and generated hydraulic pressure and arithmetically processing the difference between the generated and desired hydraulic pressures.

The electronic controlled pneumatic hydraulic pressure generator comprises a pressure converter 2 having an air piston 44 and hydraulic piston 40, a control unit 7 connected to the pressure converter 2. The control unit 7 is equipped with a controller 9 which enables the pressure converter 2 to generate a desired hydraulic pressure, an air pressure circuit having an electronic controlled air pressure valve 4 which controls the compressed air pressure and flow rate applied to the air piston 44 steplessly, an air pressure detector 34 to detect the compressed air pressure applied to the piston 44 and a hydraulic pressure detector 5 to detect the hydraulic pressure.