PROBLEM TO BE SOLVED: To save labor for evaluation of a dose distribution when irradiated with a charged particle beam based on a treatment plan. SOLUTION: A charged particle beam therapy device 1 is irradiated from an irradiation unit 103 that irradiates a charged particle beam emitted from an accelerator based on treatment plan information determined by a treatment planning device 70, and an irradiation unit 103. Irradiate the homogeneous medium corresponding to the irradiated body with the charged particle beam based on the information related to the charged particle beam by the charged particle beam information acquisition unit 104 that acquires the information related to the charged particle beam and the charged particle beam information acquisition unit 104. It has a dose distribution calculation unit 105 for calculating the dose distribution at the time of the irradiation. [Selection diagram] Fig. 3【課題】治療計画に基づいて荷電粒子線を照射した場合の線量分布の評価に係る作業を省力化する。【解決手段】荷電粒子線治療装置１は、加速器から出射された荷電粒子線を、治療計画装置７０によって定められた治療計画情報に基づいて照射する照射部１０３と、照射部１０３から照射された荷電粒子線に係る情報を取得する荷電粒子線情報取得部１０４と、荷電粒子線情報取得部１０４による荷電粒子線に係る情報に基づいて、荷電粒子線を被照射体に対応する均質媒質に照射した際の線量分布を計算する線量分布計算部１０５と、を有する。【選択図】図３
