Abstract: An electric motor, e.g., for a motor vehicle, includes an internal rotor arranged rotatably supported about a rotation axis relative to an external stator. The internal rotor includes a pot-shaped receiving sleeve arranged around a rotor shaft and an armature unit received in the rotor receiving sleeve. The armature unit includes a multiple-layered metal sheet assembly and a plurality of permanent magnets. The plurality of permanent magnets are arranged with spacing from each other in a peripheral direction at a radial outer side of the metal sheet assembly. The sheet metal assembly includes at least one retention device disposed integrally thereon in an intermediate space between adjacent permanent magnets, structured and arranged to reduce slippage of the permanent magnets in the peripheral direction.