An adhesive base material comprises a polymer obtained by polymerizing a glucosyloxy alkyl (meth)acrylate, a hydroxyalkyl (meth)acrylate, an alkyl (meth)acrylate and a polyfunctional monomer. This adhesive base material can be caused to swell uniformly because of its good swelling property and exhibits excellent adhesion to the skin so that it is useful as adhesive layers in plasters, various medical pads and also medicament-impregnated dermatologic medicines.