Utilizing random variation (repeated positioning error) when reciprocating operation is repeatedly performed in which a stage is moved by (+x, +y) pulses toward an arbitrary position perpendicular to an optical axis of X-rays extending from an X-ray source to an X-ray detector, and then, is moved from there by (−x, −y) pulses, an image group of images obtained by moving in parallel to each other is acquired, and an image processing unit finds a deviation between the images, and acquires an input image group in which each of the images has the deviation at a subpixel level. The image processing unit executes a reconstruction processing, using the input image group in which each of the images has the deviation at the subpixel level to generate a super-resolution image.