The invention relates to a method for removing horn substances from animal skin. The method is characterized in that animal skins are treated in an aqueous bath containing between 0.05 and 5 wt. %, in relation to the weight of the salt, of at least one compound of general formula I or the corresponding alkali metallic salts or alkaline-earth metallic salts thereof or ammonium or phosphonium salts. The aqueous bath also comprises at least one compound which catalyses the hydrolysis of peptide compounds ##STR00001##