PURPOSE: To obtain a magnetic recording medium having improved wear resistance, etc. by forming a surface active agent layer which is solid at an ordinary temp. and in which part of H is halogenated and part of molecular chains are crosslinked by covalent bond as a protective layer on a thin ferromagnetic metallic film formed on a substrate.

CONSTITUTION: A toluene or acetone soln. of the surface active agent which is solid at an ordinary temp. and in which part of hydrogen is substd. by F and Cl, more particularly fatty acid, alkyl allyl sulfonic acid, more preferably, the anionic surface active agent, more particularly behenic acid in which four pieces of Cl are substd. is coated on the surface of the thin ferromagnetic metallic film formed by vacuum evaporation, etc. on the substrate consisting of a polyester film, etc. and is dried and thereafter γ rays or UV rays are irradiated thereon in a gaseous N2 atmosphere to cause covalent bond of part of the molecular chains, by which the crosslinked protective layer is formed. The magnetic recording medium which has a small coefft. of friction, considerably improved still life and has good running stability is thus obtd.