1. An X-ray diagnostic apparatus comprising: an X-ray generation unit configured to generate X-rays; an X-ray detection unit configured to detect the X-rays generated by the X-ray generation unit and transmitted through an object placed on a tabletop; an X-ray beam limiting unit including a plurality of filters configured to harden radiation quality of the generated X-rays; and an X-ray beam limiting control unit configured to control the X-ray beam limiting unit to place a filter of the plurality of filters between the X-ray generation unit and the object, said filter of the plurality of filters being specified based on a thickness of the object and a distance between the X-ray generation unit and the X-ray detection unit.