However, when it is confirmed by composition analysis that Ru or the like and an insulating material such as Al2O3 are mixed together in the spacer layer 41, it may be estimated that a two-layered structure as shown in FIG. 16 is formed when film formation is performed. [0409] Next, in the step shown in FIG. 17, the lift-off resist layer 45 (see FIG. 17) is formed on the protective layer 29 shown