Abstract: It is to provide an apparatus for producing a thin film, a process for producing a thin film and a guide roller, in which an arc resistant property is provided, and the film formation can be stably conducted with preventing damage of the thin film thus formed. In an apparatus for producing a thin film, such as a plasma CVD apparatus, comprising a vacuum chamber, means for generating a plasma in the vacuum chamber, means for introducing a gas to the vacuum chamber, and a guide roller for running a material to be treated by winding and supporting in the vacuum chamber, an outer peripheral surface of the guide roller in contact and sliding with the material to be treated comprises an electric conductor on both end parts in a width direction of the guide roller, and an electric insulator on a central part thereof.

Abstract: A magnetic recording medium has a magnetic layer formed by a thin magnetic metal layer and a carbon protective layer on a non-magnetic substrate; the surface of the carbon protective layer has first protrusions formed by first particles and second protrusions formed by second particles; the carbon protective film has a thickness in the range of 3 nm to 30 nm, while the first protrusions have the heights of 65 nm.+-.15 nm to 95 nm.+-.15 nm and the second protrusions have the heights of 18 nm.+-.5 nm to 28 nm.+-.5 nm; since the surface properties of the carbon protective film are controlled, the electro-magnetic conversion characteristics may be prevented from being lowered due to the spacing losses for improving the running durability of the recording medium.