A radiation imaging apparatus has a plurality of pixels including a plurality of imaging pixels for obtaining a radiation image and a detecting pixel for detecting radiation, a plurality of column signal lines, and a detection signal line corresponding to the detecting pixel. Each of the imaging pixels includes a first conversion element configured to convert radiation into an electrical signal, and a first switch arranged between the first conversion element and a corresponding column signal line among the plurality of column signal lines. The detecting pixel includes a second conversion element configured to convert radiation into an electrical signal, and a second switch arranged between the second conversion element and the detection signal line.
