Provided is a neutron capture therapy apparatus (lA) including: an accelerator (10) which emits a charged particle beam (P)； atarget (T) which is irradiated with the charged particle beam (P)to generate a neutron beam (N)； a beam transport path (48) that transports the charged particle beam(P), which is emitted from the accelerator (10), to the target (T) ； and a current detection portion (60) which detects a current value of the charged particle beam (P). The current detection portion (60) is provided inside the beam transport path (48) along an inner wall (48a) of the beam transport path (48) in a state of being insulated by the inner wall (48a).本發明的課題為提供一種能夠檢測帶電粒子束相對於靶之照射位置是否正常之中子捕捉療法裝置。一種中子捕捉療法裝置(1A)，其具備：加速器(10)，射出帶電粒子束(P)；靶(T)，受到帶電粒子束(P)的照射而產生中子束(N)；射束傳輸線路(48)，向靶(T)傳輸從加速器(10)射出之帶電粒子束(P)；及電流檢測部(60)，檢測帶電粒子束(P)的電流值；電流檢測部(60)在射束傳輸線路(48)的內部以與射束傳輸線路(48)的內壁(48a)絕緣之狀態沿著內壁(48a)設置。
