Аннотация:We report here results of the comparative study of different gamma-ray spectrometers, that are using modern type scintillating crystals like LYSO, YSO, LaBr3:Ce, CeBr3 and Ce:GAGG. Energy resolution of gamma-ray detectors as derived for different combinations of scintillating crystals and photo-sensors that were exposed to the conventional set of radioactive isotopes, as well, as their potential use will be discussed in this paper.We also present an example of gamma-ray spectrometer application in the long-term measurements of flux and spectral variations of the sea level gamma-ray background radiation. The instrument contained moderately large (80x80 mm) scintillating detector with energy resolution ~7% at 662 keV. The data stream was recorded in event-by-event mode with ~15 µs time resolution thus permitting detection of the terrestrial gamma-ray bursts at the moment of lightning during thunderstorms. Real time calibration of the spectrometer during the whole experiment was performed using 40K background line position (E=1.46 MeV). This set-up helps to exclude temperature variations of the signal in a long-term experiment. The instrument design, as well, as the results of its long-term employment are discussed in this paper.