A solenoid-operated fluid control valve has an armature assembly which includes a reciprocally movable platelike magnetic valve member and a seal element loosely retained by the valve member and projecting therefrom. A magnetic core defines a fluid passageway and has a valve seating surface at its one end. The valve seating surface of the magnetic core opens in a valve chamber which surrounds the side surface of the magnetic valve member to guide its movement toward and away from the valve seating surface and to maintain the seal element in alignment with the valve seating surface. The seal element has opposed conical or spherical ends and an annular recess therebetween. The seal element loosely engages with and retained by an opening of the magnetic valve member to abut concentric with the valve seating surface of the magnetic core in spite of a slight eccentricity of the assembly within the valve chamber. The solenoid-operated fluid control valve also has a compression spring positioned concentric with the magnetic valve member and bears at one end against the magnetic valve member and a solenoid mounted on a bobbin in which the magnetic core is secured.