The sonoluminescence spectra of water saturated with helium, argon, krypton, and xenon gases were studied in a 220-500 nm interval. Total light power of sonoluminescence and the yield of hydrogen peroxide increased in the order He < Ar < Kr < Xe. The peak position of the OH* radical at 310 nm did not depend on the dissolved gas, but in the region lambda < 310 nm the light emission had maxima at 262, 268, 250, and 242 nm for He, Ar, Kr, and Xe, respectively. The intensity of this part of the spectra increased in the same order. The results show that sonoluminescence is a kind of luminescence, and the source of sonoluminescence is not blackbody radiation or electrical discharge.