A rotary actuator for setting the rotation angle of control elements, especially of a throttle device which determines the flow cross-section in a line through which flow passes, for internal-combustion engines, having an electric actuating motor with a two-pole stator, stator winding and two-pole permanent-magnet rotor. In order to achieve a compact construction and manufacture which is easy in production-engineering terms, the stator poles are constructed as claw poles which are connected on opposite end sides in each case to an annular jacket for the magnetic return path, which jacket surrounds the claw poles with a radial gap. The stator winding is located as an annular coil in the annular space between the annular jacket and the claw poles. In order to produce latching of the permanent-magnet rotor outside the claw pole gaps when no current is flowing in the stator winding, the claw poles are designed asymmetrically in such a manner that, on the one hand, the radial air gap width in the central claw pole region is greater than in the two claw pole edge regions and the radial widths of the claw pole edge regions are a different size.