To produce a magnetic functionally gradient material in which martensitic transformation is caused in a gradient manner by applying stainless steel with strain in a gradient manner and to optimumly control the magnetic gradient.

Wedgy austenitic stainless steel is applied with compressive deformation in a plane strain state at a liquid nitrogen temperature to cause ununiform strain in the material, and martensitic transformation accompanying the strain is ununiformly caused, by which a magnetic functionally gradient material in which saturation magnetization accompanying the martensitic transformation is changed in a gradient manner, simultaneously, hardness accompanying the martensitic transformation is changed in a gradient manner, and simultaneously, corrosive characteristics accompanying the martensitic transformation is changed in a gradient manner is produced.