Abstract: The invention relates to a disk motor with an armature disk, which is rotatably mounted and provided with permanent magnets, and with a stator which comprises a stator plate which is equipped with coils. The aim of the invention is to provide a disk motor that is as flat as possible and that is characterized by an improved smoothness of running. To this end, an annular soft-magnetic prestressing device is arranged concentrically on the stator plate in such a manner that at least one section of the prestressing device is located below the coil window of the coils in the axial direction. The armature disk may support an annular flux-return element opposite which the annular prestressing device is located in the radial direction. Said prestressing device has a cross-sectional contour that guides the magnetic lines of electric flux from the annular flux-return element to the coil window.