THE PRESENT INVENTION RELATES TO A BACKING HAVING A THREE-LAYER STRUCTURE PREPARED BY STICKING TOGETHER AN INNER FIBER LAYER FOR HOLDING A PASTY PREPARATION, A FILM LAYER HAVING THROUGH-HOLES, AND AN AIR-PERMEABLE OUTER FIBER LAYER WHICH PREVENTS LEAKING OUT OF THE PASTY PREPARATION OR A LIQUID COMPONENT EXUDED FROM THE PASTY PREPARATION, AND ALSO RELATES TO AN AQUEOUS PATCH USING THE BACKING WHICH CAN BE APPLIED FOR A LONG TIME.