An adjustment method of a plane of rotation possesses has a step (S62) of detecting a range of the first X-rays from the X-ray tube 125 positioned at a first position with an X-ray detector 70; a step of moving the X-ray tube from the first the position to a second position; a step of detecting a range of the second X-rays from the X-ray tube positioned at the second the position with the X-ray detector 70; a step (S64) of calculating quantity of adjustment of the X-ray tube 125 and the collimator 126 based on the detected ranges by the first X-rays and the second X-rays.