Silver indium sulfide thin films have been successfully synthesized out from beta-In2S3 buffer layers using appropriate heat treatments of evaporated beta-In2S3/Ag. X-ray analysis show that the beta-In2S3/Ag crystalline films with GO nm thickness of Ag, which were annealed under sulfur atmosphere at 400 degrees C, were mainly formed by the ternary AglnS(2). Raman spectra confirmed that the observed peaks were characteristics to AglnS2 chalcopyrite of thin film structure. The optical band gap of AglaS(2), which was evaluated as nearly 1.80 eV, was confirmed by the electrical study which yielded a value in the order of 1.78 eV. The electrical conductivity, conduction mechanism, dielectric properties and relaxation model of this thin film were studied using impedance spectroscopy technique in the frequency range 5 Hz-13 MHz under various temperatures (370-440 degrees C). Besides, complex impedance, AC conductivity and complex electric modulus have been investigated on the basis of frequency and temperature dependence. (C) 2014 Elsevier B.V. All rights reserved.