A method for producing (i) a photocatalytic material having wear resistance and sliding properties, (ii) a photoelectric conversion element material having wear resistance and sliding properties, (iii) a slide-resistant material, or (iv) a wear-resistant material, the method comprising the steps of: forming titanium nitride on the surface of a metallic titanium material or a titanium alloy material by one treatment method selected from the group consisting of heat treatment under ammonia gas atmosphere and heat treatment under nitrogen gas atmosphere, at a heating temperature of 750°C or more, wherein the reaction pressure of the heat treatment is 0.1 to 10 MPa, and the heating time of the heat treatment is 10 minutes to 8 hours; anodizing the metallic titanium material or titanium alloy material with the titanium nitride formed on the surface thereof obtained in step by applying a voltage of 10 V or more in an electrolyte solution that does not have an etching effect on titanium, thereby forming a titanium oxide film, wherein the anodization treatment temperature is 10 to 50°C, and the electrolyte solution that does not have an etching effect on titanium used in anodization is an electrolyte solution containing at least one compound selected from the group consisting of phosphoric acid and phosphate; wherein the electrolyte solution is phosphoric acid at a concentration of 0.1 to 10 wt.% or phosphoric acid and phosphate at a total concentration of 0.1 to 10 wt.% the anodizing time is 10 seconds to 30 minutes, and the anodizing voltage is 50 to 300 V and the anodizing is not accompanied by spark discharge phenomena, and heating the metallic titanium material or titanium alloy material with the titanium oxide film formed on the surface thereof obtained in step at a temperature of 400°C or more in an atmosphere selected from an air oxidizing atmosphere, an atmosphere of a mixture of oxygen gas and nitrogen gas, and an oxygen gas atmosphere, wherein the reaction pressure of the heat treatment is 0.01 to 5 MPa. forming titanium nitride on the surface of a metallic titanium material or a titanium alloy material by one treatment method selected from the group consisting of heat treatment under ammonia gas atmosphere and heat treatment under nitrogen gas atmosphere, at a heating temperature of 750°C or more, wherein the reaction pressure of the heat treatment is 0.1 to 10 MPa, and the heating time of the heat treatment is 10 minutes to 8 hours; anodizing the metallic titanium material or titanium alloy material with the titanium nitride formed on the surface thereof obtained in step by applying a voltage of 10 V or more in an electrolyte solution that does not have an etching effect on titanium, thereby forming a titanium oxide film, wherein the anodization treatment temperature is 10 to 50°C, and the electrolyte solution that does not have an etching effect on titanium used in anodization is an electrolyte solution containing at least one compound selected from the group consisting of phosphoric acid and phosphate; wherein the electrolyte solution is phosphoric acid at a concentration of 0.1 to 10 wt.% or phosphoric acid and phosphate at a total concentration of 0.1 to 10 wt.% the anodizing time is 10 seconds to 30 minutes, and the anodizing voltage is 50 to 300 V and the anodizing is not accompanied by spark discharge phenomena, and heating the metallic titanium material or titanium alloy material with the titanium oxide film formed on the surface thereof obtained in step at a temperature of 400°C or more in an atmosphere selected from an air oxidizing atmosphere, an atmosphere of a mixture of oxygen gas and nitrogen gas, and an oxygen gas atmosphere, wherein the reaction pressure of the heat treatment is 0.01 to 5 MPa. <EOS>