PROBLEM TO BE SOLVED: To perform CT imaging of a subject in a standing state while holding the subject in a predetermined position.SOLUTION: An X-ray tomographic imaging apparatus includes a frame body, a support pillar, and a fixing tool. The frame body includes an opening forming an imaging space, and includes an X-ray tube and an X-ray detector. The support pillar supports the frame body in a state that a central axis of the opening is oriented in a vertical direction with respect to a floor surface so as to move it in the vertical direction. The fixing tool fixes a subject holding tool so that the subject holding tool is disposed in a passage route of the opening, and part of the subject holding tool is included in the opening at a stage that the subject holding tool is mounted on the subject.SELECTED DRAWING: Figure 3COPYRIGHT: (C)2018,JPO&INPIT【課題】立位状態の被検体を所定位置に保持してCT撮影すること。【解決手段】本実施形態に係るX線コンピュータ断層撮影装置は、架台本体、支柱及び固定具を有する。架台本体は、撮影空間を形成する開口を有し、X線管とX線検出器とを有する。支柱は、前記開口の中心軸が床面に対して垂直方向に向いた状態の前記架台本体を前記垂直方向に移動可能に支持する、固定具は、被検体保持具を被検体に装着する段階において、前記被検体保持具が前記開口の通過経路に配置され且つ前記被検体保持具の一部が前記開口に含まれるように前記被検体保持具を固定する。【選択図】 図3