This X-ray diagnostic device is provided with a top plate, a top plate supporting body, an arm, a position storage unit, and a mechanism control unit. A subject is placed on the top plate. The top plate supporting body supports the top plate such that the top plate is able to move in the lengthwise direction, standing and reclining direction, and up and down direction. The arm holds an X-ray tube for emitting X-rays to the subject placed on the top plate and an X-ray detector for detecting the X-rays, that passed through the subject, such that the X-ray tube and the X-ray detector can move in the near-to-far direction relative to the top plate supporting body. The position storage unit stores the imaging position of the arm and the imaging position of the top plate in association with one another each time the subject is imaged. A mechanism control unit moves the top plate in the standing and reclining direction and the up and down direction so as to maintain the location, at least in the up and down direction, of a site of the subject corresponding to the imaging position of the arm stored in the position storage unit when the position of the arm is in a retreating position in which it is impossible to irradiate the subject on the top plate with X-rays.Linvention concerne un dispositif de diagnostic à rayons x comprenant une plaque supérieure, un corps de support de plaque supérieure, un bras, une unité de stockage de position et une unité de commande de mécanisme. Un sujet est placé sur la plaque supérieure. Le corps de support de plaque supérieure supporte la plaque supérieure de telle sorte quelle peut de se déplacer dans le sens de la longueur, dans le sens vertical et incliné et vers le haut et vers le bas. Le bras maintient un tube à rayons X destiné à émettre des rayons X sur le sujet placé sur la plaque supérieure et un détecteur de rayons X détecte les rayons X qui traversent le sujet, de telle sorte que le tube à rayons X et le détecteur de rayons X peuve
