An X-ray imaging apparatus including an X-ray generation means and an X-ray detector on which a plurality of different types of grids is removably mountable. The X-ray detector includes an automatic exposure control (AEC) detector which detects the quantity of X-rays emitted from the X-ray generation means and outputs a signal based on the detected quantity. The X-ray imaging apparatus also includes control means controlling the X-ray generation means based on the signal output from the AEC detector, and correcting the AEC detector output according to the type of grid used.
