A neutron capture therapy (NCT) device is disclosed, which is able to conduct proper treatment when encountering a current value drop during a transmission of charged particle beam. The NCT device 1 has: a first current detector (11) for detecting the current of charged particle beam (P), and a second current detector (32), which is nearer than the first current detector (11) to a lower stream side, used for detecting the current of charged particle beam (P). Accordingly, when the current value of the charged particle beam (P) drops between the second current detector (32) and the first current detector (11), a differential will be produced between the first current value and the second current value. Therefore, when the differential is greater than a threshold, the disclosed is able to control a transmission of the charged particle beam (P) from an accelerator (10) by a control section (100), thereby controlling appropriately in corresponding to the current value drop of the charged particle beam (P). Hence, the disclosed is able to conduct proper treatment when encountering a current value drop during a transmission of charged particle beam (P).本發明提供一種中子捕捉療法裝置。前述中子捕捉療法裝置能夠在帶電粒子線的傳輸中發生電流值降低的情況下進行適當的治療。前述中子捕捉療法裝置1具有：第1電流測定部(11)，測定帶電粒子線(P)的電流；第2電流測定部(32)，在比第1電流測定部(11)更靠下游側測定帶電粒子線(P)的電流。依這種結構，在第2電流測定部(32)與第1電流測定部(11)之間發生帶電粒子線(P)的電流值降低的情況下，在第1電流值與第2電流值之間產生差分。因此，在該差分大於臨限值的情況下，藉由控制部(100)對來自加速器(10)的帶電粒子線(P)的射出進行控制，能夠進行與帶電粒子線(P)的電流值的降低對應的適當的控制。藉此，能夠在帶電粒子線(P)的傳輸中發生電流值降低的情況下進行適當的治療。
