A dynamoelectric machine having mechanical field weakening is provided. A design that is advantageous in terms of efficiency is brought about by a machine having a stator (1), a rotor (2) that is spaced from the stator (1) by an air gap (8), permanent magnets (4) for generating an exciter field in the air gap (8), which permanent magnets are arranged in magnet pockets (3) on the rotor (2), and displaceable flux-guiding elements (10) guided in radially extending grooves (12), wherein the density of the exciter field in the air gap (8) can be influenced by the radial position of the flux-guiding elements, and wherein the leakage flux-guiding elements (10) are arranged underneath the permanent magnets (4) when viewed in a radial direction.