The invention relates to a pneumatic open- and closed-loop control apparatus (10) for flows of pressure fluid, having one inlet conduit (14), two outlet conduits (16, 18), and one venting conduit (20), and also having a valve piston (90) mediating between these conduits and mounted in a valve chamber (92), and to a method for open- and closed-loop control of flows of pressure fluid. It is proposed that by means of a pneumatically driven valve piston (92), with a predeterminable time constant, one outlet conduit (16, 18) each of the pneumatic open- and closed-loop control apparatus (10) is connected to the single inlet conduit (14), while the other outlet conduit is simultaneously connected to the venting conduit (20).