A radiation imaging apparatus comprising a plurality of sensors arrayed to form a plurality of rows and a plurality of columns on a substrate and a driving unit configured to drive the plurality of sensors row by row, wherein the driving unit performs a first operation of driving the plurality of sensors while selecting the plurality of rows in a first order, and a second operation of driving the plurality of sensors while selecting the plurality of rows in a second order different from the first order after the first operation, such that a time difference is produced between a sensor in each row and a sensor in a neighboring row from the selection in the first order to the selection in the second order.