A thin aqueous cataplasm prepared by laminating an adhesive layer (base) having specified constituents on a support which consists of a fiber film prepared by heat-fusing a soft plastic resin on a composite fiber prepared by entangling a natural fiber and a soft plastic fiber, or consists of a fiber film prepared by heat-fusing a plastic resin having a soft part and a hard part in common on a fiber consisting of a plastic having a soft part and hard part in common. The thin aqueous cataplasm retains a moisture-protecting effect on the skin and provides comfortable feeling in its use.