Abstract: In a method of finishing a surface of a floating type magnetic head in which a sliding contact surface opposing a magnetic recording medium is made of a polycrystal material comprising at least two kinds of phases of different compositions mixed together, the sliding contact surface is roughened by treatment with an etching solution in accordance with a chemical etching process. The sliding contact surface of the floating type magnetic head can be mirror-finished with an appropriate surface roughness, so that satisfactory CSS performance and good electromagnetic performance can be obtained. The sliding contact surface is preferably made of a polycrystal ceramic material selected from the CaTiO.sub.3 ceramic system, the AlTiC ceramic system and the MnO-NiO ceramic system. The etching solution contains aqueous hydrogen peroxide as an oxidizing agent and is preferably an aqueous hydrogen peroxide and ammonia solution.

Abstract: A thin film made of hydrogenated amorphous silicon oxide ?a-SiO.sub.x :H! (x=1.0 to 1.8) is formed on an upper surface of a slider and an upper surface of a head core of a magnetic head, in which the thickness of the thin film is set at 1 nm to 20 nm.