A radiation imaging apparatus comprising: a plurality of pixels (102, 110) arranged in an array in an image sensing region and configured to obtain a radiation image corresponding to a radiation irradiation dose; at least one first detecting element and at least one second detecting element each including a conversion element configured to convert radiation into an electrical signal to obtain radiation irradiation information, corresponding to radiation irradiated to the radiation imaging apparatus, including at least one of start of radiation irradiation, end of radiation irradiation, a radiation irradiation intensity, or a radiation irradiation dose; a first signal line to which a signal from the first detecting element is to be output and a second signal line to which a signal from the second detecting element is to be output; and a signal processing circuit configured to process the signal output from the first detecting element via the first signal line and the signal output from the second detecting element via the second signal line, wherein the first signal line and the second signal line are arranged in the image sensing region or arranged adjacent to the image sensing region, a sensitivity of the second detecting element to convert radiation into an electrical signal is lower than that of the first detecting element, wherein the first detecting element has a larger region to detect radiation than the second detecting element, and the signal processing circuit generates the radiation irradiation information based on a difference between the signal from the first signal line and the signal from the second signal line. a plurality of pixels (102, 110) arranged in an array in an image sensing region and configured to obtain a radiation image corresponding to a radiation irradiation dose; at least one first detecting element and at least one second detecting element each including a conversion element configured to convert radiation into an electrical signal to obtain radiation irradiation information, corresponding to radiation irradiated to the radiation imaging apparatus, including at least one of start of radiation irradiation, end of radiation irradiation, a radiation irradiation intensity, or a radiation irradiation dose; a first signal line to which a signal from the first detecting element is to be output and a second signal line to which a signal from the second detecting element is to be output; and a signal processing circuit configured to process the signal output from the first detecting element via the first signal line and the signal output from the second detecting element via the second signal line, wherein the first signal line and the second signal line are arranged in the image sensing region or arranged adjacent to the image sensing region, a sensitivity of the second detecting element to convert radiation into an electrical signal is lower than that of the first detecting element, wherein the first detecting element has a larger region to detect radiation than the second detecting element, and the signal processing circuit generates the radiation irradiation information based on a difference between the signal from the first signal line and the signal from the second signal line.