In order to widen the adjustment range for pressure regulation in a brake system fitted with a brake servo-unit capable of being operated (preferably electromagnetically) independently of the driver's will, the following arrangement is proposed: the hydraulic pressure (PTHz) set in a master cylinder (3) downstream of the brake servo-unit (2) is determined and applied to a pressure regulator (8) following comparison with a pressure setting signal (PSoll); the output value (ISt) of the pressure regulator matches a control current for the electromagnet (7) and is applied to a limiter (12) which sets the boundary values of the desired adjustment range and whose initial value (ISoll) is compared with the value of the current (IEM) applied to the electromagnet (7); the result (IRegel) of the comparison is applied to a current regulator (14) which produces the voltage (UEM) destined to be applied to the electromagnet (7).