According to one embodiment, an X-ray diagnostic apparatus includes an X-ray movable diaphragm and processing circuitry. The X-ray movable diaphragm limits an irradiation field of an X-ray. The processing circuitry sets an FOV size related to the irradiation field, sets a virtual field of view having the FOV size, the virtual field of view being able to include an outside region of an X-ray detection region and at least a part of the X-ray detection region, and controls the X-ray movable diaphragm so as to apply the X-ray to a common region between the virtual field of view and the X-ray detection region.
