Onset of electric current has been detected on illuminating the near–contact regions of RbAg4I5crystals. The spectral and temperature characteristics of this current have been studied. A method is proposed for studying the spectrum of electronic states in the α-phase of the RbAg4I5crystal. The dependence of the magnitude of the current and its spectral characteristics on the particular region of the RbAg4I5crystal which is exposed to the light was used for the analysis of the variations in the distribution of defects along the length of the sample and the processes which occur near the electrode-(solid electrolyte) junctions.