A neutron beam detection apparatus includes a scintillator configured to generate light when a radial ray is incident thereon, an optical fiber configured to cause light generated in the scintillator to be transmitted therethrough, and a discrimination section configured to receive light transmitted through the optical fiber and to discriminate a detection signal from a signal related to a neutron beam when a wave height of a detection signal related to the received light exceeds a determination threshold value Q th . The discrimination section adjusts the determination threshold value in accordance with deterioration of the optical fiber.本發明提供一種中子束檢測裝置及中子捕捉療法裝置。本發明的中子束檢測裝置具備：閃爍器，若有放射線入射則產生光；光纖，傳送在閃爍器中產生之光；及辨別部，接收藉由光纖傳送之光，當有關所接收之光之檢測信號的波高超過判定閾值(Qth)時，將檢測信號辨別成有關中子束的信號，辨別部依據光纖的劣化調整判定閾值。
