An x-ray diagnostic device of an embodiment of the present invention is equipped with the following: an image pick-up unit comprising an x-ray tube for emitting x-rays to a subject and an x-ray detector for detecting the x-rays that pass through the subject an x-ray aperture unit that is disposed between the x-ray tube and the x-ray detector, and that has a plurality of aperture blades and is rotatable an image processing unit for generating a transparent image of a region of interest set according to the x-ray aperture unit and a control unit that controls individually the plurality of aperture blades so that the long side of the opening formed by the plurality of aperture blades is oriented in the longitudinal direction of a target object in the transparent image.
