A composition for the etching treatment of a resin molded article. The composition is composed of an aqueous solution containing 20 to 1,200 g/l of an inorganic acid, 0.01 to 10 g/l of a manganese salt, and 1 to 200 g/l of at least one component selected from the group consisting of halogen oxoacids, halogen oxoacid salts, persulfate salts, and bismuthate salts. The etching composition of the invention is an etching solution capable of forming a plating film having a good adhesion to various resin molded articles made of ABS resins or the like, and can be used in place of chromic acid mixtures. The composition is highly safe so that the liquid waste is easily disposed of.