Abstract: The present invention discloses a stent for supporting a sidewall of a lumen which contains a first fluid. The stent comprises a stent body, a film and a photosensitizing layer. The stent body is disposed inside the lumen. The film is adapted to be penetrated by a light and covers the stent body. The photosensitizing layer is disposed on an outer surface of the film for receiving the light to generate a first object, and the film separates the photosensitizing layer and the first fluid. The film and the photosensitizing layer of the present invention can greatly reduce the needed dosage of the photosensitizer while maintaining the effective concentration of the photosensitizer around tumor cells.