The invention provides a rotary solenoid, comprising a stator and rotor that can rotate around a rotational axis, wherein the rotor has a rotor shaft on which a rotor disc is arranged, and the rotor disc, seen in the direction of circumference, has alternating magnetically polarized magnetic poles. The stator carries at least one coil carrying windings for conducting electric current. Between the coil and the rotor disc is a pole face having at least of two partial pole faces for guiding the magnetic flux of the magnetic field generated by the windings when current is applied. Elements of the magnetic system (the magnetic poles, the partial pole faces and the air gap) are configured along the direction of circumference depending on the rotational angle changeable in such a way that a torque results that returns the rotor in the starting position, when the current is switched off.