A material that is useful as a wear-resistant member, a highly functional photocatalytic material, a photoelectric conversion element material, etc., is produced without the need for complicated processes or complicated handling, which are problems of the prior art. Provided is a method for producing a surface-treated metallic titanium material or titanium alloy material, the method comprising the steps of (1) forming titanium nitride on the surface of a metallic titanium material, and (2) heating the metallic titanium material with titanium nitride formed on the surface thereof obtained in step (1) in an oxidizing atmosphere. Also provided is a method for producing a surface-treated metallic titanium material or titanium alloy material, the method comprising, between steps (1) and (2) above, the step of anodizing the metallic titanium material with titanium nitride formed on the surface thereof obtained in step (1) in an electrolyte solution that does not have an etching effect on titanium, thereby forming a titanium oxide film. Further provided is a surface-treated material.