Chlorine-substituted perovskite Ba3.95In2Zr2O10.9Cl0.1 was obtained for the first time, and its single phase was confirmed by X-ray diffraction method. The obtained perovskite has a cubic structure and is a proton conductor at T <650°C and p (H2O) = 2×10-2 atm. It is shown that doping with chlorine makes it possible to increase the oxygen-ion and proton conductivity.