OF THE DISCLOSUREPARTICLE BEAM IRRADIATION SYSTEM AND CHARGED PARTICLE BEAM CORRECTION METHOD Provided is a particle beam irradiation system capable of enhancing the beam utilization efficiency without deteriorating the uniformity of the irradiation dose. A particle beam irradiation system, comprising a synchrotron in which an ion beam is accelerated and from which the ion beam is then extracted and an irradiation device for irradiating a target volume with the ion beam extracted from the synchrotron and performing one-unit irradiation multiple times, is equipped with: cumulative beam charge quantity measurement means which measures a cumulative beam charge quantity (Qmeas) in the synchrotron； target current setting means which sets a target beam current value (Ifb) for beam current extracted from the synchrotron based on the cumulative beam charge quantity (Qmeas) measured by the cumulative beam charge quantity measurement means； and extraction beam current correction control means which controls the beam current based on the target value (Ifb) of the extraction beam current determined by the target current setting means.本發明係一種粒子線照射系統及荷電粒子束之補正方法，其課題為提供未使照射輻射劑量一樣度降低而可提高射束利用效率之粒子線照射系統。其解決手段為具有加速離子束(10)而射出之同步加速器(13)，和照射從同步加速器(13)所射出之離子束(10)之照射裝置(30)，從照射裝置(30)複數次進行一單位之照射的粒子線照射系統，其特徵為具備：計測同步加速器(13)內之儲存射束電荷量(Qmeas)之儲存射束電荷量計測手段(15)，和依據以儲存射束電荷量計測手段計測之儲存射束電荷量(Qmeas)，設定從同步加速器(13)射出之目標射束電流值(Ifb)之目標電流設定手段，和依據從前述目標電流設定手段所求得之射出射束電流之目標值(Ifb)而控制射束電流之射出射束電流補正控制手段者。
