In an electric cable, designed for an electric winding, such as a transformer or reactor winding, an electrically conducting core (2) is arranged to be in contact with an inner, first semiconducting layer (4) surrounding the core. A first insulating layer (6) is arranged on the outside of the first semiconducting layer surrounding it. An outer, second semiconducting layer (8) is arranged on the outside of the first insulating layer surrounding it. Means (16, 18) are also provided on the outside of the second semiconducting layer to earth the cable for alternating voltage and/or impulse voltage continually along at least a substantial part of its length.