PURPOSE:To obtain the titled substance useful as a coloring material, etc., smoothly, rapidly and in good productivity, by blending copper powder with an organic dibasic acid solid at normal temperature a weakly acidic aqueous solution containing a volatile organic acid and a powder filler such as alumina, etc., in a specific composition and sufficiently reacting them in an atmosphere. CONSTITUTION:(A) 100pts.wt. copper powder is blended with (B) 10-200pts.wt. organic dibasic acid solid at normal temperature, (C) 20-300pts.wt. weakly acidic aqueous solution containing 4-20pts.wt. volatile organic acid and (D) 5-300pts.wt. filler which is inorganic substance powder which is powder of alumina, silica, silicate, aluminate or inorganic substance comprising them as a main component and/or powder of starch, cellulose, its derivative, chlorinated rubber, thermoplastic synthetic resin, synthetic fiber, natural fiber and reacted in atmosphere or under a condition in contact with carbon dioxide for a sufficient time to give the aimed verdigris-like substance.
