The following are obtained by the present invention: an X-ray CT device enabling the acquisition of measurement images at rotation angles of at least 180 degrees, regardless of the arrangement, movement trajectory, and movement range of an X-ray source and a detector; and highly accurate images. A measurement image detected by the detector is converted to a rotation measurement image obtained by rotationally moving the X-ray source and the detector on a concentric circular trajectory. Weighting, to which is imparted intensity change equal to a reconfiguration image obtained from a rotation measurement image obtained by measurement at the rotation angle range of 180 degrees, is applied to the measurement angles of a rotation measurement image, reconfiguration calculation is carried out, and a reconfiguration image is obtained.