A rotational drive sensor 31 which allows a radiation source 10 and a twomensional sensor 20 which are caused to be in one body to turn round a subject 50. An X-ray vessel 13 irradiates X-rays to the subject 50 in a pulsated manner. An X-ray/light conversion element 21 converts an X-ray transmitted image to an optical image. A CCD camera 23 picks up this optical image. An information processing unit 40 reconstructs a three-dimensional pictorial image on the basis of two dimensional pictorial images in plural directions obtained, and a display monitor 46 displays this three-dimensional pictorial image. A controller 39 controls the distance between the X-ray vessel 13 and the X-ray/light conversion element 21 and the focal size of the X-ray vessel 13 on the basis of the size of the subject 50. As a result, it is possible to obtain, in a short time, a three-dimensional pictorial image having less distortion and high resolution in a broad region, and to reduce X-ray exposure quantity to much more degree as compared to the conventional system.