A pressure-sensitive adhesive base which contains the liquid organic ingredient and which, despite this, has moderate pressure-sensitive adhesion properties (tackiness and cohesive force) and causes no bleeding. It hardly injures the keratin of the skin and is inhibited from irritating the skin. The pressure-sensitive adhesive base comprises the following ingredients (A) to (C): (A) a copolymer comprising units of a monomer containing a carboxy group and units of a (meth) acrylic ester (B) one or more, liquid or semisolid organic compounds which are compatible with the copolymer of the ingredient (A) and (C) at least one member selected among polyvalent-metal oxides and polyvalent-metal hydroxides, the total content of the ingredient (C) being 0.001-5 mass % based on the whole pressure-sensitive adhesive base. The adhesive base contains substantially no water.
