A method for manufacturing a piston ring includes the following steps:



(A) a step of supplying an arc current to a cathode formed of a carbon material having a density of 1.70 g/cm3 or more, to ionize the carbon material; and
(B) a step of applying a bias voltage in an environment where hydrogen atoms are substantially absent to form a DLC film on a surface of a base material for a piston ring.




The step (A) is continuously carried out, subsequently the step (A) is interrupted, and then the step (A) is restarted, which sequence is repeated thereby to form the DLC film having an extinction coefficient of 0.1 to 0.4 as measured using light having a wavelength of 550 nm and a nanoindentation hardness of 16 to 26 GPa.