A radiation detecting cassette includes a casing having first through fourth display units mounted on respective side walls thereof for displaying ID information of a patient, etc. The casing also has first detectors on the respective side walls for detecting obstacles facing the first through fourth display units and second detectors on the respective side walls for detecting loads applied to the casing near the first through fourth display units. Based on detected results from the first and second detectors, at least one of the first through fourth display units which is not covered by the patient is selected to display the ID information of a patient, etc.