Abstract: A method for nitriding materials using a glow discharge in an atmosphere of nitrogen or gas mixture at a pressure between 1 . . . 100 mtorr (0.13 . . . 13.3 Pa). Nitriding treatment can be combined with a plasma aided coating process and the temperature control during both processes can be achieved with the aid of separate filament. Nitriding unit can be a separate rig or a part of the coating unit. The method can be used to increase the wear resistance of a work piece by increasing the hardness of its surface. Because of the low pressure used in the nitriding process the same equipment can be used to produce a separate hard and wear resistant compound or alloy coating on the nitrided surface to further increase the hardness of the uppermost surface. The main field of the method is in increasing the wear and corrosion resistance of machine parts and tools.