This magnetic recording medium is characterized in that in the magnetic recording medium having a magnetic layer on a non-magnetic substrate by intercalating at least an under layer, the proportion of functional groups per 100 carbon atoms in a diamond-like carbon protective layer mainly composed of carbon for protecting the magnetic layer exceeds 20%. The ceramic insulator includes a front portion with a stepped outer surface, a middle portion, a rear portion and a shoulder portion defined between the middle and rear portions. Additionally, each icon may be visually similar to its respective input component.