A pressure control system is used for eliminating individual differences of a plurality of pressure controllers used for controlling pressures of a plurality of pressure-controlled sections. The pressure control system includes a plurality of pressure controllers for supplying a pressurized fluid to a plurality of pressure-controlled sections, a master pressure controller for supplying a pressurized fluid having a reference pressure, a plurality of calibration chambers corresponding to the pressure controllers. The pressure control system further includes differential-pressure detecting devices provided in the calibration chambers to detect a differential pressure between the pressurized fluid supplied from the master pressure controller and the pressurized fluid supplied from the pressure controller, and an arithmetic device configured to receive a signal from the differential-pressure detecting device and adjust an output of the pressure controller so that the above differential pressure becomes zero or approximately zero.