Abstract: A method and device for explosives identification bombards a sample with neutrons the energy of which is to the positron activation energy of nitrogen and to the required energy for a neutron proton nuclear reaction of neutrons with 16O to 16N. Electron positron annihilation radiation emitted by the sample due to the neutron bombardment is then detected as a function of time. The respective concentration and the concentration ratio of oxygen and nitrogen in the sample is determined from the time dependency of the annihilation radiation, and the explosive is identified by the comparison of the concentration ratios of the specific concentrations of oxygen and nitrogen with the corresponding substance ratios of known explosives. By radiation with neutrons at the same time radionuclides 13N are created from the nitrogen contained and 16N from the oxygen contained, the decay of which generates electron positron annihilation radiation with characteristic half-lives.