PURPOSE: To adhere a magnetic thin film of a main magnetic pole close to a magnetic layer of a medium easily without working the main magnetic pole highly accurately by forming the leading ends of the main magnetic pole and an auxiliary magnetic pole in a cylindrical form having curved surfaces in the direction rectangular to the track width direction of the main magnetic pole.

CONSTITUTION: The leading ends of the auxiliary magnetic pole 8 and the main magnetic pole 9 are worked into a cylindrical form having their curved surfaces in the direction rectangular to the track width direction, i.e. the thickness direction of the magnetic thin film 10. When a medium is inserted between both magnetic poles with fixed load, the magnetic thin film 10 of the main magnetic pole 9 is always adhered close to the surface of the medium easily with a fixed interval. Even if a slight projection is formed on the surface of the medium, the main magnetic pole is prevented from floating due to the projection when the curvature of the leading ends of the magnetic poles is slightly small. Since the auxiliary magnetic pole 8 is linearly contacted with the main magnetic pole 9 at the surfaces of the cylinders, the magnetic thin film 10 of the main magnetic pole 9 can be made contact with the medium over the whole surface of the track width.