<p>An X-ray CT apparatus which executes a first X-ray tomography on a sectional plane having a desirable thickness in an object to be examined ( 0 ) with the object interposed between an X-ray generator ( 1 ) and a two-dimensional X-ray image sensor ( 2 ) provided so as to hold their mutual facing positional relation, and also executes a second X-ray tomography for obtaining a CT image of the interested area of the object ( 0 ). The first X-ray tomography is executed on the object ( 0 ) while the object ( 0 ) is held and fixed by an object holder ( 4 ) with the center of the orbit of the X-ray circulating radiation fixed, and while the object holder ( 4 ) is moved by an object mover ( 5 ) along the X-ray sectional image forming path according to the rotary angle of the X-ray circulating radiation.</p>
