Abstract: A fuel injector for fuel injection systems of internal combustion engines has an electromagnetic actuating element including a magnet coil, a tubular internal pole and an external magnetic circuit part, a valve sleeve having an internal opening and thin walls and a movable valve closing body which works together with a valve seat assigned to a valve seating body. The valve seating body and the internal pole are fixedly arranged in the internal opening in the valve sleeve . The internal pole has a longitudinal slot formed by producing it by rolling and/or bending.