To provide a magneto-resistance effect magnetic head capable of coping with high density recording by forming an extremely thin insulating film while securing an excellent insulation.

An ion bean deposition device 10 is used, which comprises a 1st grid gun 11 for sputtering a target 30 by emitting an ion beam accelerated by grids 23, 24 against the target 30, and a 2nd grid gun 12 for etching the substrate 31 by emitting the ion beam accelerated by the grids 27, 28 against the substrate 31. And, after the substrate 31 has been etched by making the 2nd grid gun ON, an insulating film is deposited on the substrate 31 by making the 2nd grid gun 12 OFF and performing sputtering by the 1st grid gun 11.