Abstract: In order to produce the electric insulation of the winding of an electric machine, grooves having a cross-section that tapers at least in an area near to the groove opening are arranged in the rotor or motor. Before the winding is laid in the grooves, the latter are lined with a laminate that contains an elastically compressed mass of high-elastic, electrically insulating fibres and a solidified, curable synthetic resin that can still be thermally softened, however, and that holds the mass of fibres in its compressed state. Once the winding is laid and the grooves are closed, the rotor or stator is subjected to a vacuum pressure impregnation, then cured.