PURPOSE: To prevent the generation of dissolution and corrosion in a washing stage for FeMn which is an antiferromagnetic material layer by using weakly alkaline washing water in a washing stage in production of the MR head.

CONSTITUTION: After the antiferromagnetic material layer 16 consisting of the FeMn is formed on a magneto-resistance effect layer (MR layer) 13, a resist 15 is removed and the antiferromagnetic material layer 16 is patterned by a lift-off method. The antiferromagnetic material layer is then subjected to the washing stage after the end of the patterning and thereafter, an electrode layer 17 consisting of W, etc., is formed on the antiferromagnetic material layer 16 and is similarly washed after the patterning. The FeMn which is the essential component of the antiferromagnetic material layer 16 is easily attacked by ultrapure water, concd. ultrapure water, pure water, city water, etc., but is relatively strong to alkalis. Then, the corrosion thereof is prevented by executing washing by using the weakly alkaline washing water of 7 to 10 pH.