FIELD: dosimetry of fast and thermal neutrons and gamma-radiation. SUBSTANCE: invention is designed for use in complexes and systems of radiation monitoring. Given detector is manufactured in the form three scintillators in multiple-series connection. External neutron scintillator is made from organic hydrogen-carrying substance sensitive to fast neutrons based on plastic material (CH)n or stilbene (scintillator with well) and scintillation crystal Nal-Tl placed in well of external scintillator in standard container sensitive to gamma radiation. Internal scintillator is based on 6Li-soda-lime glass activated with cerium sensitive to thermal neutrons placed in one case with photoelectric multiplier. Electronic signal processing unit incorporates circuit of time selection of scintillation pulses coming from neutron-sensitive scintillators and from gamma-sensitive scintillator. Detector also includes spectrometric analyzer to process scintillation pulses coming from scintillation crystal Nal-Tl. Detector provides for counting of neutrons and for spectrometric analysis of gamma-quanta. EFFECT: higher capability of separate registration of fast and thermal neutrons. 2 cl, 1 dwg.