In an X-ray device 1 according to the present invention, an imaging position of a pre-image P is corrected on the basis of a correction amount calculated by a correction amount calculation unit 29. The correction amount is calculated on the basis of a distance between a center Ko of a vertebral body region that a characteristic region extraction unit 27 extracts from the pre-image P and a center Po of the pre-image P. When the pre-image is generated, the pre-image is corrected such that the center Ko of the vertebral body region coincides with the center Po of the pre-image P. Additionally, a pre-image generation instruction button 33a is depressed to generate the pre-image P by single irradiation of a pulse X-ray from an X-ray tube 5. Regardless of the depression time, the X-ray irradiation time is set to be a prescribed short time at all times so that X-ray irradiation time can be made to be a prescribed short time reliably with a simple operation. As a result, when setting the imaging region of an X-ray image for measurement, the time for X-ray irradiation can be reduced, minimizing exposure of a subject. Further, since the imaging position of the pre-image P can be corrected quickly, the time required to capture the X-ray image for measurement can be reduced.Dans un dispositif à rayons X (1) selon la présente invention, une position d'imagerie d'une pré-image P est corrigée sur la base d'une quantité de correction calculée par une unité de calcul de quantité de correction (29). La quantité de correction est calculée sur la base d'une distance entre un centre Ko d'une région de corps vertébral qu'une unité d'extraction de région caractéristique (27) extrait de la pré-image P et un centre Po de la pré-image P. Lorsque la pré-image est générée, la pré-image est corrigée de telle sorte que le centre Ko de la région de corps vertébral coïncide avec le centre Po de la pré-image P. De plus, un bouton d'instruction de génération de pré-image (33a) est enfoncé pour génér
