PURPOSE: To obtain a patterning method in which magnetic and chemical stability of a magnetic film is not damaged by stacking a CoPt film onto patterned Si or Cr and by stacking another Cr or Si thereupon.

CONSTITUTION: Film A is either Si or Cr, and film B is either Si or Cr which is not the film A. (a) Film A is formed onto a substrate, and film B is stacked thereupon. Then film B is patterned, and a Co100-xPtx film (40≤X≤60wt.%) is stacked thereupon. (b) The Co100-xPtx film is formed onto a substrate, and film A is stacked thereupon and patterned, on which film B is further stacked. (c) The said processes (a) and (b) are repeated several times. Either one of processes (a) to (c) is made. Then such stacked film is thermally treated at 450°C for more than 15 minutes. For example, a CoPt film 2 is formed onto a substrate 1 and then an Si film 4 is stacked through a Cr pattern which is formed on the film 2. Then a thermal treatment is made thereto and the CoPt film is magnetically patterned.