Energy spectra of the accelerated electron beams for 50 shots measured in spectrometer 1 located 2.3-m downstream of the gas target. Electron beams with an average peak energy of about 490 MeV, r.m.s. energy spread of 0.2–1.2%, r.m.s. divergence of 0.1–0.4 mrad and charges of 10–50 pC were experimentally obtained. The associated fluctuations of the electron beam peak energy were estimated to be less than 3%.