A composite film comprises a drug sustained-release portion and an adhesive portion which are layered on each other. The drug sustained-release portion has film-like drug layers and a film-like biodegradable polymer layer. The drug sustained-release portion has the drug layer, the biodegradable polymer layer, and the drug layer in this order from the adhesive portion side. Each drug layer is a drug form containing a drug of a predetermined concentration or more. The drug is released from the drug layer exposed. When the drug layer disappears, a biodegradable polymer of the biodegradable polymer layer starts to degrade and/or dissolve. When the biodegradable polymer layer disappears, the drug is released from the drug layer adjoining the adhesive portion. A plurality of pores are formed in the adhesive portion. The pores retain water due to capillary force.
