An imaging region including a plurality of detection elements each including a conversion element configured to convert radiation into an electric signal, a first signal line, and a signal processing circuit configured to process a signal output via the first signal line, wherein the plurality of detection elements include a first detection element and a second detection element which are connected to the first signal line, a sensitivity of the first detection element to radiation is set to be different from a sensitivity of the second detection element to radiation, and the signal processing circuit generates information related to irradiation of radiation to the imaging region based on signals from the first detection element and the second detection element which are connected to the first signal line.