A detector designed to register γ-quanta emitted in spontaneous fission of nuclei is described. It was used together with a neutron detector with 3He counters designed to register rare events of spontaneous fission. An additional γ-ray detector used with the neutron detector permitted the increase of information on every event registered. It allowed a decrease of the background when detecting spontaneous fission rare events. For a detection efficiency for spontaneous fission ∊ = 0.8 (for 252Cf) the detector background was about one event, in which one neutron and not less than three γ-quanta were registered per day. Energy spectra and distributions over multiplicity of γ-quanta of spontaneous fission in 252Cf are presented.