PURPOSE: To improve the shear due to the lapse of time in the bonding of organic substances, the deterioration in the magnetic characteristic due to an inorganic adhesives and the bonding strength between layers by forming a coil and a magnetic layer or an MR element to the opposite side of a gap by means of the thin film process so as to constitute a closed magnetic path.

CONSTITUTION: Ferrite cores 13, 14 are bonded by welding of glass and a magnetic gap G is formed at the same time, then a ceramic block 15 is bonded by a low melting point glass and a glass packing part 16 is formed by the same glass at the same time. Then a slot reaching the ceramic block 15 is cut by a desired track width and track pitch, the glass is packed again to the slot, the block is cut off finally at a required height (h) and a thin film forming face D is finished by mirror surface lap. An insulation layer 7, a coil 18 and a magnetic layer 19 are formed on a plane D constituted by the bulk head by the thin film process, a protection layer is formed further on it and R processing to the plane C is applied. Thus, the deterioration of the thin film magnetic characteristic and of the bonding strength is eliminated to improve the reliability.