A radiation imaging apparatus includes a detection unit that detects radiation applied by a radiation generating apparatus, an automatic exposure control unit that determines whether to stop application of radiation based on an accumulated dose of the detected radiation and to notify the radiation generating apparatus of an instruction to stop the application of radiation in a case where it is determined to stop the application of radiation, a plurality of memories, and a memory control unit that stores, in a first memory from among the plurality of memories, data to be used when the automatic exposure control unit makes the determination.

A radiation imaging apparatus includes a detection unit that detects radiation applied by a radiation generating apparatus, an automatic exposure control unit that determines whether to stop application of radiation based on an accumulated dose of the detected radiation and to notify the radiation generating apparatus of an instruction to stop the application of radiation in a case where it is determined to stop the application of radiation, a plurality of memories, and a memory control unit that stores, in a first memory from among the plurality of memories, data to be used when the automatic exposure control unit makes the determination.