Abstract: The objective of the present invention is to provide a hydrogel having a favorable shape stability not only after releasing an anionic drug contained but also in the process of releasing such an anionic drug, compared with the conventional techniques; and an anionic drug-containing ophthalmic device obtained by applying the hydrogel. The objective can be achieved by an anionic drug-containing ophthalmic device comprising: (1) an anionic drug; and (2) a copolymer which comprises a cationic monomer and a monomer capable of copolymerizing with the cationic monomer, wherein the cationic monomer comprises, as a structural component, a condensation product of (meth)acrylic acid with an aminoalkyl quaternary ammonium compound having a substituted or unsubstituted aralkyl group, or a salt of the condensation product; and the like.