A radiation imaging apparatus that obtains a radiation image by an energy subtraction method. Each pixel includes a conversion element that converts radiation into an electrical signal and a reset portion that resets the conversion element. Each pixel performs an operation of outputting a first signal corresponding to an electrical signal generated by the conversion element in a first period, and an operation of outputting a second signal corresponding to an electrical signal generated by the conversion element in the first period and a second period. Radiation having first energy is emitted in the first period, and radiation having second energy is emitted in the second period. In each pixel, the reset portion does not reset the conversion element during a period that includes the first period and the second period.
