Abstract: A member for a plasma processing device includes: an aluminum base material; and an oxide film formed on the aluminum base material and having a porous structure, the oxide film including a first oxide film formed on a surface of the aluminum base material, a second oxide film formed on the first oxide film, and a third oxide film formed on the second oxide film, wherein the first oxide film is harder than the second oxide film and the third oxide film, and a hole formed in each of the first oxide film, the second oxide film and the third oxide film is sealed.

Abstract: With the purpose of forming an anodic oxide coating that is given conductivity or other new functions on the surface of aluminum-based material with high productivity, anodizing of aluminum-based material (2) is performed in an anodizing bath containing sulfuric acid together with nitrate ion to form a porous anodic oxide coating on the surface of the aluminum-based material (2). In another processing step, if electroplating is performed after anodizing, silver or a silver compound or other metal (7) can be electroplated from an electroplating bath without dissolving and removing the barrier layer from the bottom (6) of the pores (3) of the porous anodic oxide coating (1).