An actuator, wherein an axial force is used as an output, said actuator consists of: a housing, a lamellated stator wound with a single-phase winding and an armature representing a part of the actuator movable in a linear direction and consisting of an axle and a magnet , supported on the axle , wherein the magnet is a two pole radially magnetized cylindrical permanent magnet and wherein the magnet is separated by a radial air gap from the stator , wherein the shape of the radial air gap is defined by two notches provided in the stator , wherewith the direction of the magnetic field on the magnet in a non-excited state of the stator winding is offset by a certain angle from a direction in which the stator magnetic field is produced when the stator winding is excitated, characterized in that , the axle is supported in the housing by a second set of sliding bearings for linear shifting of the axle relative to the stator and the axle is blocked to rotation around its axis, wherein the magnet is supported on the axle by a first set of sliding bearings and is coupled with the axle via a screw connection formed as a thread on the axle and as a nut on the magnet for centering the magnet and the axle , and for rotary and linear movement of the magnet relative to said axle , whereby by an alternate excitation of the single phase winding of the stator , a torque on the magnet is generated thereby shifting the magnet via the screw connection and the first set of sliding bearings in linear direction along the axle and by shifting the magnet , the static characteristic of the actuator is regulated, when the actuator acts as a magnetic spring. a housing, a lamellated stator wound with a single-phase winding and an armature representing a part of the actuator movable in a linear direction and consisting of an axle and a magnet , supported on the axle , wherein the magnet is a two pole radially magnetized cylindrical permanent magnet and wherein the magnet is separated by a radial air gap from the stator , wherein the shape of the radial air gap is defined by two notches provided in the stator , wherewith the direction of the magnetic field on the magnet in a non-excited state of the stator winding is offset by a certain angle from a direction in which the stator magnetic field is produced when the stator winding is excitated, characterized in that , the axle is supported in the housing by a second set of sliding bearings for linear shifting of the axle relative to the stator and the axle is blocked to rotation around its axis, wherein the magnet is supported on the axle by a first set of sliding bearings and is coupled with the axle via a screw connection formed as a thread on the axle and as a nut on the magnet for centering the magnet and the axle , and for rotary and linear movement of the magnet relative to said axle , whereby by an alternate excitation of the single phase winding of the stator , a torque on the magnet is generated thereby shifting the magnet via the screw connection and the first set of sliding bearings in linear direction along the axle and by shifting the magnet , the static characteristic of the actuator is regulated, when the actuator acts as a magnetic spring. <EOS>