Abstract: An electromagnetically actuated piston slide valve (1) with proportional characteristic comprises an axially movable piston (5) for closing radial passage openings (7). So as to change, with a cross-sectional area of the fluid passage openings (7) given by the magnetic drive, a parabolic course of the pressure loss at an increasing flow rate into a largely linear to degressive course, there is provided a pressure-sensing bore (9), which connects the fluid entrance side, at which pressure P1 is present, with the fluid exit side, at which pressure P2 is present. In the pressure-sensing bore (9) is axially displaceably disposed a pressure-sensing pin (10) and pushes, when pressure P1 is greater than pressure P2, the slide piston (5) into its open position. Thereby the free cross-sectional area of the fluid passage openings (7) increases, and the pressure loss ?P=P1?P2 decreases correspondingly.