To provide a technology for improving the wear resistance, durability and adhesive properties of a hard carbon film applied on the surface of machine parts strongly applied with thermal and mechanical impact.

A layer (metallic gradient layer) in which metal has been added to a hard carbon film so as to give a gradient to the volume ratio in such a manner that the volume ratio on the surface side of the hard carbon film is controlled to ≤30%, and the volume ratio of the lower layer side, i.e., the side of a base material (machine parts) of the hard carbon film is controlled to ≥50% is provided on the lower layer. The film thickness of the metallic gradient layer is controlled to 0.5 to 5 μm. As for the hard carbon film other than the metallic gradient layer, the volume ratio of the metal is controlled to ≤30%, and the film thickness is controlled to 0.5 to 5 μm. Moreover, the hard carbon film may be composed only of the metallic gradient layer.