Method for insulating coating a stator which is designed in the form of a hollow cylinder with radially inwardly directed webs on its inner wall, wherein - a nozzle unit which is movable relative to the stator and which is adapted to the shape of the internal cross-sectional geometry of the stator is moved inside the stator along its longitudinal axis, wherein a flowable, mouldable insulating material is applied to the webs of the stator and into the grooves formed between the webs by injection moulding through radially outwardly directed outlet openings of the nozzle unit, thereby forming a thin-walled electrical insulation coating, - the stator is inserted into a hollow cylindrical injection moulding tool middle part, which is closed at the end face and/or can be closed by means of a cover part, wherein when the stator is inserted, a gap region is formed on its first (1.1) and second (1.2) end walls to the end walls of the injection moulding tool middle part, which gap region is filled with flowable, mouldable insulating material during the relative movement of the nozzle unit and the stator, - firstly, a first gap region between the first inner end wall of the injection moulding tool middle part or a cover part arranged on the end face of the injection moulding tool middle part and the first end wall (1.1) of the stator is filled with insulating material to form a first end-face cover layer on the stator, then the stator is coated on its entire inside while moving relative to the nozzle unit, and finally the second gap region between the second end wall of the injection moulding tool middle part and the second end wall (1.2) of the stator is filled with insulating material to form a second end-face cover layer on the stator. - a nozzle unit which is movable relative to the stator and which is adapted to the shape of the internal cross-sectional geometry of the stator is moved inside the stator along its longitudinal axis, wherein a flowable, mouldable insulating material is applied to the webs of the stator and into the grooves formed between the webs by injection moulding through radially outwardly directed outlet openings of the nozzle unit, thereby forming a thin-walled electrical insulation coating, - the stator is inserted into a hollow cylindrical injection moulding tool middle part, which is closed at the end face and/or can be closed by means of a cover part, wherein when the stator is inserted, a gap region is formed on its first (1.1) and second (1.2) end walls to the end walls of the injection moulding tool middle part, which gap region is filled with flowable, mouldable insulating material during the relative movement of the nozzle unit and the stator, - firstly, a first gap region between the first inner end wall of the injection moulding tool middle part or a cover part arranged on the end face of the injection moulding tool middle part and the first end wall (1.1) of the stator is filled with insulating material to form a first end-face cover layer on the stator, then the stator is coated on its entire inside while moving relative to the nozzle unit, and finally the second gap region between the second end wall of the injection moulding tool middle part and the second end wall (1.2) of the stator is filled with insulating material to form a second end-face cover layer on the stator.