Abstract: In a method and apparatus for determining neutron spectra using at least two neutron detectors which provide integral counting rates from which the spectrum of a neutron radiation can be approximated, and which consist each of a semiconductor diode, a converter layer, an inactive layer and an active layer. The various layers of each detector are different from those of the other neutron detector and so selected that the sensitivity functions of the two neutron detectors are different. An artificial neutral network is provided which is especially trained and to which the counting rates of the detectors are supplied to be processed for obtaining the neutron spectrum.