The invention describes an electrical machine comprising a stator and a rotor which is separated from the stator by an air gap and has a plurality of shell-like magnet segments which are fastened to a magnetic return path element. In this case, the magnet segments are arranged opposite one another in pairs in each case and each have a plurality of magnetically differently polarized sections in the circumferential direction, said sections each forming a magnetic pole of the rotor. In this case, recesses which each serve as outer detached pole portions are provided on that side which faces the stator in the edge zones of the magnet segments which are arranged in the circumferential direction. Furthermore, further recesses are provided on that side which faces the stator in the transition zones between the magnetically differently polarized sections of the magnet segments, said recesses serving as inner detached pole portions.