ccording to another aspect of the present invention, there is provided, as shown in FIG. 0, an X-ray computerized tomography apparatus, comprising: an X-ray detection unit 00 for detecting transmission X-rays from a plurality of directions irradiated from an X-ray beam generation source 00 and transmitted through a subject; a data acquisition unit 00 for acquiring transmission data according to the transmission X-rays detected by the X-ray detection unit; an object position detection unit 00 for detecting a position of an object inside the subject, according to a part of the transmission data acquired by the data acquisition unit: a visualizing-range detection unit 00 for determining a slice in which an image should be visualized, according to the position detected by the object position detection unit; an image reconstruction unit 00 for reconstructing a tomographic image, according to the transmission data acquired by the data acquisition unit; and a display unit 00 for visualizing the tomographic image of a slice determined by the visualizing-range detection unit. Further, according to still another aspect of the present invention, there is provided, as shown in FIG. 00, an X-ray computerized tomography apparatus, comprising: an X-ray detection unit 00 for detecting transmission X-rays from a plurality of directions irradiated from an X-ray beam generation source 00 and transmitted through a subject; a data acquisition unit 00 for acquiring transmission data according to the transmission X-rays detected by the X-ray detection unit; an object position detection unit 00 for detecting a position of an object inside the subject, according to a part of the transmission data acquired by the data acquisition unit: a