A fundamental study of a new concept for surface modification of metal surfaces based on two consecutive processes – metal coating and plasma nitriding – is conducted in order to obtain thin plasma-nitrided diffusion layers on austenitic stainless steels enriched with the metal from the coating, with superior surface characteristics with respect to the bipolar plate application of proton-exchange membrane fuel cells. The special feature of the concept is that the metal coating is permeable to the nitrogen diffusion into the base material.Austenitic stainless steel sheets EN 1.4301 with a thickness of 0.1mm are coated with chromium films in the range of 5–200nm by means of magnetron sputtering deposition. Subsequently, short-time plasma-nitriding by means of the strip hollow-cathode method is applied. The diffusion layers are analysed taking into account the nitrogen diffusion into the base material, diffusion processes at the interface between the chromium coating and the base material, the distribution of the elements, and the phase formation, in particular the formation of chromium nitrides. Further investigations are performed to determine the influence of applied plasma treatment on the electrical conductivity and corrosion resistance of the stainless steel surfaces.