To enable an abnormality related to a gantry to be detected appropriately.SOLUTION: A charged particle beam medical treatment device 1 having an irradiation unit for irradiating a charged particle beam includes: a gantry 14 where an irradiation unit is disposed, which can rotate with a predetermined axis line as a center an X-ray tube 15 and an X-ray detector 19 attached to the gantry 14, which function as an imaging unit for imaging an imaging object and an abnormality determination unit 21 for determining presence and absence of an abnormality related to the gantry 14 based on an image captured by the imaging unit. The abnormality determination unit 21 determines the presence and absence of an abnormality related to the gantry based on a position of an image of the imaging object in a plurality of images captured by the imaging unit in a state that the angles of the gantry 14 are different from each other.SELECTED DRAWING: Figure 3【課題】ガントリに係る異常を適切に検出することを可能とする。【解決手段】荷電粒子線を照射する照射部を有する荷電粒子線治療装置1であって、照射部が配置され、所定の軸線を中心として回転可能なガントリ14と、ガントリ14に取り付けられて、撮像対象物を撮像する撮像部として機能するX線管15及びX線検出器19と、撮像部により撮像された画像に基づいて、ガントリ14に係る異常の有無を判定する異常判定部21と、を有し、異常判定部21は、ガントリ14の角度が互いに異なる状態で撮像部により撮像された複数の画像における撮像対象物の像の位置に基づいて、ガントリに係る異常の有無を判定する。【選択図】図3
