This invention relates to an aqueous etching composition for etching metallic copper comprising(a) an acid,(b) a copper complexing agent,(c) a metal capable of having a multiplicity of oxidation states which is present in one of its higher positive oxidation states and which metal forms a composition soluble salt, and(d) oxygen wherein the concentration of the higher positive oxidation state metal in the composition is greater than about 4 grams/liter of composition.The invention also relates to a process for etching metallic copper comprising contacting the surface of a copper substrate with the aqueous etching compositions of the invention. A method of regenerating a spent aqueous etching composition of the invention which has been used for etching metallic copper also is described.