Abstract: To provide an aqueous adhesive for an inorganic material with excellent adhesiveness to the inorganic material. An adhesive improver (J) for an aqueous adhesive for an inorganic material including a copolymer (A) containing an unsaturated (poly) carboxylic acid (anhydride) (a1) and a (meth) acrylic acid alkyl (2 to 30 alkyl carbon atoms) ester (a2) as a constituent monomer; and an aqueous adhesive for an inorganic material (X) including the adhesive improver (J), saccharide (B), a polycarboxylic acid (C) having 4 to 24 carbon atoms and water.