A magnetic-field-applying bias film having strong-magnetic-field resistance includes an exchange coupling film. The exchange coupling film includes a ferromagnetic layer and an antiferromagnetic layer stacked on the ferromagnetic layer. The antiferromagnetic layer includes an X(Cr—Mn) layer containing Mn, Cr, and one or more elements X selected from the group consisting of platinum-group elements and Ni. The X(Cr—Mn) layer has a first region relatively close to the ferromagnetic layer and a second region relatively far from the ferromagnetic layer. The Mn content in the first region is higher than the Mn content in the second region.