The present invention provides a kind of neutron-capture therapy device and neutron beam measuring method, and aforementioned neutron-capture therapy device can immediately detect neutron dose, and inhibit the decline of the measurement accuracy of neutron beam. The device has: instant dosage output section (40), has to detect neutron beam (N) and the immediately scintillation detector (41) of output signal and will be converted to neutron dose and immediately the neutron dose output section (44) of output neutron dose from the signal of scintillation detector (41) output using correction coefficient (45)； And correction coefficient configuration part, it sets correction coefficient (45). Correction coefficient configuration part has: to detect due to illuminated neutron beam from the λ ray detection portion of the λ ray emitted by the gold thread of activation Hou, and be foundation: the dosage of the signal and the neutron beam obtained according to the λ ray detected by λ ray detection portion that export by illuminated neutron beam from scintillation detector (41) is modified correction coefficient (45).本發明提供一種中子捕捉療法裝置及中子束測定方法，前述中子捕捉療法裝置能夠即時地檢測中子劑量，並抑制中子束的測定精度的下降。該裝置具備：即時劑量輸出部(40)，其具有用以檢測中子束(N)並即時地輸出訊號之閃爍檢測器(41)及利用校正係數(45)將從閃爍檢測器(41)輸出之訊號轉換為中子劑量並即時地輸出中子劑量之中子劑量輸出部(44)；及校正係數設定部，其設定校正係數(45)。校正係數設定部具備：用以檢測因被照射中子束而從被放射化後之金線所發射之λ射線之λ射線檢測部，並且是依據：藉由被照射中子束而從閃爍檢測器(41)所輸出之訊號、及根據被λ射線檢測部所檢測到之λ射線而獲得之中子束的劑量來對校正係數(45)進行修正。
