PURPOSE: To provide the characteristics such as corrosion resistance, lighter weightness and spring characteristic which a titanium or titanium alloy possesses by providing a finishing treatment stage for finishing and treating the parts subjected to a plating removing stage.

CONSTITUTION: A stage 10 for applying nickel plating over the entire surface of the titanium or titanium alloy parts formed in a stage 1 for forming the titanium or titanium alloy parts is provided and a stage 12 for brazing and joining the parts to be brazed and joined is provided. The plated parts are removed by a chemical treatment, etc., in the plating removing stage 13 for exposing the stock surfaces of the titanium or titanium alloy by removing the plating on the outside surfaces of the titanium or titanium alloy parts subjected to the stage 12. A finish plating treatment stage, ion plating, coloration treatment by electrodeposition painting and oxidation treatment by heating, etc., are executed in the finishing treatment stage 14 for finishing the parts subjected to the stage 13. The nickel-plated parts having poor corrosion resistance are thereby removed and the various conditions including the lighter weightness, corrosion resistance and spring characteristics are satisfied.