A method of producing a protective film on recording media including forming a protective film on at least the surface facing a recording medium, said protective film having the composition represented by the formula: SiC.sub.XH.sub.YO.sub.ZN.sub.W, where X=3-26, Y=0.5-13, Z=0.5-6 and W=0-6, in terms of atomic ratio, having a film thickness of 1-3 nm and having a refractive index of 2.0 or more.