PURPOSE: To form a high hardness and/or low friction layer by evaporating a metal from a metallic target material by arc discharge and converting the evaporated metal into metallic plasma with a gaseous phase of ionized carbon.

CONSTITUTION: A target material kept at a certain electric potential is converted into target plasma in vacuum and this plasma is allowed to reach a substrate kept at a higher electric potential than the target material to form a layer. At this time, the target material is made of a metal such as Ti, Zr, Hf, V, Mo or W and this metal is evaporated by arc discharge and converted into metallic plasma with a gaseous phase of ionized carbon. The ionization of carbon is carried out by subjecting hydrocarbon such as methane, propane or acetylene to glow discharge. Up to about 90% of the evaporated metal can be ionized.