To improve measurement accuracy of a position of a tube focus in radiation imaging more easily in a radiation imaging apparatus.

The radiation imaging apparatus includes a radiation source 30 for emitting radiation, a radiation detector 20 for detecting radiation which is emitted from the radiation source 30 and is transmitted through a subject 1A, a shifting means 10 for holding and shifting the radiation source 30 in a direction parallel to a detection surface 20M of the radiation detector 20, and an acceleration sensor 40S for obtaining a position of the tube focus 30F in the radiation source 30. The acceleration sensor 40S is integrally disposed in the neighborhood of the radiation source 30, and radiation imaging is performed while shifting the radiation source 30 by the shifting means 10.