Provided is a method for detecting damage to a deck of a bridge, the method allowing detection work to be achieved with less labor and being capable of reducing the time and cost needed for the detection work. The intermediate transfer medium and the optical disk are laid so that the surface of the intermediate transfer medium carrying the image and the surface of the optical disk are in close contact with each other. The cartridge has a trigger mechanism which acts in concert with a notched lever and a wedge-shaped arm internally located in the cartridge to sequentially load the dosage cavity with medicament and discharge it. A dummy sequence inserter inserts the dummy sequence into a subband in the position.