A coating composition including an amide group-containable macromolecule compound (A) having an amide group or to have an amide group and an anti-oxidizing material (B) capable of inhibiting oxidation of the amide group. The amide group-containable macromolecule compound (A) is an amide group-containing polymer (a1) having an amide group and an aromatic ring, and/or an amide group-containing-polymer precursor (a2) to convert into the amide group-containing polymer (a1) by baking at a time of coating with said coating composition. The anti-oxidizing material (B) accounts for 0.1 to 20 mass % of a total amount of said amnide group-containable macromolecule compound (A) and the anti-oxidizing material (B).