After the MR effect multilayer 332??? is formed as described above, an insulating layer 335 of a material such as Al2O3 or SiO2 with a thickness of approximately 3-20 nm and a bias layer 336 of a material such as CoFe, NiFe, CoPt, or CoCrPt are formed, in sequence, by using a method such as sputtering as shown in FIG. 8 d.