PURPOSE: To suppress a lubricant from being dried up by setting a roughness of the surface of a magnetic layer to a specified value by changing spattering and vapor-depositing conditions, making it comparatively porous, and impregnating the porously formed magnetic layer with the lubricant.

CONSTITUTION: A vertical ferromagnetic material thin film 2 of a cobalt chrome alloy is formed by 1μm on a polyester film 1 by a magnetron spattering method. An electrochemical etching treatment is executed in a dilute sulfuric acid solution so that a magnetic material layer surface 2a becomes to have a roughness of 50W200, a lubricant 3 is impregnated onto said surface, and a lubricant layer 4 is formed. In this case, a thickness 5 of the rough surface part of the magnetic material layer and the lubricant layer 4 is 400 at most from the viewpoint of an electromagnetic conversion characteristic, and about 200W 300 is desirable.