To improve seizure resistance of a hard film composed of a TIN or a mixture of TIN and Ti for coating a piston ring and to thicken the film.

A gas nitriding layer 2 is formed on whole surface of a piston ring 1 and a hard film 3 composed of a TIN or a mixture of a TIN and Ti is coated on the gas nitriding layer 2 on the outside circumference of the piston ring 1 in the thickness of 1 to 80 μm. The hard film 3 presents a columnar structure of a crystal of the rupture surface in the axial direction of the piston ring 1 growing from the parent metal side toward the film surface side and the TIN crystal has a precedent azimuth of the 111 surface or the 200 surface in parallel to the coated surface, while the hardness is within the range of HV900 to 2000 Vickers hardness.