Abstract: In the metallic thin film magnetic recording medium having the magnetic layer formed on a main face of a nonmagnetic supporting body according to vacuum thin film formation technology, the thickness of the nonmagnetic supporting body is 5 &mgr;m or less, the thickness of the magnetic layer is 20 nm-100 nm and a lining layer 20 nm-200 am in thickness is formed of metal, non-metal or alloy of these materials or oxide compound thereof according to vacuum thin film formation technology. Light transmittance is 5% or less and permeating water vapor amount is 5 g/m2·day or less. The lining layer and the back layer are formed successively on a main face opposite to the magnetic layer formation face. The relative roughness factor (Ra) of the topmost surface of the lining layer formation face is 2-15 nm.

Abstract: A metallic thin film magnetic recording medium having a magnetic layer formed on a main face of a nonmagnetic supporting body according to vacuum thin film formation technology, wherein the thickness of the nonmagnetic supporting body is 5 &mgr;m or less and the thickness of the magnetic layer is 20 nm-100 nm, the metallic thin film magnetic recording medium further comprising a lining layer having the thickness of 20 nm-200 nm formed on a main face opposite to said magnetic layer formation face, of metal, non-metal or alloy or oxide compound thereof according to the vacuum thin film formation technology.