An actuator device having an expansion unit (10), which comprises a magnetically active shape memory alloy material (12) and which carries out an expansion movement from a starting position along an expansion direction as a reaction to an energization of a coil device (30) and interacts with restoring means which exert on the expansion unit (10) a restoring force opposite to the expansion direction, wherein the restoring force has permanent magnets which act or are seated on a section of the expansion unit (10) such that the restoring force generated magnetically by the permanent magnets changes with increasing expansion stroke in the expansion direction, wherein the permanent magnets (16, 34, 40, 52, 54) are embodied and/or designed such that the expansion unit (10) can contract into the starting position along the expansion stroke when the coil device (30) is not energized.