Translated from Prib. Tekn. Eksp.; 16: No. 4, 38-40(1973). The possibility is demonstrated of measuring the relative energy of gamma quanta from the decays of pi /sup o/ mesons having momenta of up to several tens of GeV/ c. The energy was determined according to the blackening density of the images of electronphoton lines from a spark spectrometer on photographic film. The standard deviation was 15% for gamma quanta having energies of 10 to 40 GeV. (auth)