PURPOSE: To obtain a nonmagnetic substrate for magnetic heads for vapor- depositing metallic magnetic films.

CONSTITUTION: This nonmagnetic substrate for magnetic head is composed basically of CoO and NiO or NiO with at least one of the oxides of Sr, Ba, and Ra by 0.1-10wt.% of the said component. When such composition is used, the coefficient of thermal expansion and hardness of the substrate become nearly equivalent to those of a magnetic film structure in which the substrate is incorporated. Therefore, the occurrence of delamination and cracking in the magnetic film structure can be prevented. When the hardness is further improved, in addition, the shortening of the service life of magnetic heads and deformation, cracking, etc., of the nonmagnetic substrate can be suppressed and the wear resistance and durability of the heads can be improved.