The invention relates to an electrotechnical core for producing a cold atmospheric-pressure or low-pressure plasma for the treatment of human and/or animal and/or technical surfaces. The electrotechnical core has a side facing the surface to be treated and a side facing away from the surface to be treated and comprises the following layers arranged one over the other, starting from the side facing the surface to be treated: a first insulation layer； a first electrode structure, which is connected to a first contacting means in order to establish electrical contact between the first electrode structure and an energy supply unit and which is grounded during operation； a second insulation layer, which is designed to galvanically isolate the first electrode structure and a second electrode structure from each other； a second electrode structure, which is connected to a second contacting means in order to establish electrical contact between the second electrode structure and an energy supply unit and which, during operation, is driven by a voltage signal that is provided by an energy supply unit and that is sufficient for generating a plasma； a third insulation layer, which is designed to galvanically isolate the second electrode structure and a third electrode structure from each other； a third electrode structure, which is provided with a third contacting means for grounding the third electrode structure during operation.
