In the radiography system, a camera provided in an X-ray source captures a camera image indicating a usage environment in which an electronic cassette is used. The electronic cassette is inserted into the field of view of the camera. An in-image cassette region of the electronic cassette is detected from the camera image. A cassette ID of the electronic cassette is acquired from the in-image cassette region. The acquired cassette ID is collated with registration information set in a console and a use cassette setting process is performed on the basis of the collation result.