An electromagnet having a hollow cylindrical coil former fitted with a coil winding and surrounded by a magnet housing. The coil former is bounded by upper and lower pole shoes. A nonmagnetic metal tube in the hollow cylinder of the magnet defines an armature space for a magnet armature that divides the armature space into first and second chambers, which are connected via a pressure equalizing channel in the magnet armature. A push rod passes through an axial hole in the lower pole shoe, to a control piston of a hydraulic valve, whose interior is connected via a further pressure equalizing channel in the lower pole shoe to the first chamber of the armature space. The push rod is a profiled rod contacting the magnet armature, the rod is of a cross-sectional shape different than that of the axial hole in the lower pole shoe and of a cross-sectional area less than that of the axial hole. The magnet armature has a central longitudinal hole of a diameter smaller than the largest profile width and larger than the smallest profile width of the push rod.