Disclosed is a device of neutron capture therapy, which is able to release an improvement in reliability of boron neutron capture therapy (BNCT). The device of neutron capture therapy (1) irradiates a neutron beam (N) to an irradiated object (M), which makes boron and neutron inside the irradiated object (M) to react. The device of neutron capture therapy (1) has a structure as follows: a neutron beam irradiation section (4) for irradiating neutron beam (N) to an irradiated object (M)； and a boron concentration measuring section (32) for measuring the degree of boron concentration inside the irradiated object (M) in real time when the neutron irradiation section (4) irradiates the neutron beam (N).本發明提供一種中子捕捉療法裝置，其能夠實現硼中子捕捉療法之可靠性之提高。本發明之中子捕捉療法裝置(1)對被照射體(M)照射中子束(N)，使被照射體(M)內的硼和中子進行反應，前述中子捕捉療法裝置(1)為如下結構，具備：中子束照射部(4)，對被照射體(M)照射中子束(N)；及硼濃度測定部(32)，由中子束照射部(4)照射中子束(N)時即時測定被照射體(M)內的硼的濃度。
