Three-layered ceramic membranes based on stabilized zirconia for planar solid-oxide fuel cell (SOFC) are prepared by the tape casting method. The outer layers containing 94 mol % ZrO2–6 mol % Sc2O3 provide the enhanced mechanical stability; the inner layer has the composition of 89 mol % ZrO2–10 mol % Sc2O3–1 mol % Y2O3 which has the highest anionic conductivity in the series of solid solutions ZrO2–Y2O3–Sc2O3. Studying the mechanical characteristics shows that the ultimate strength (bending strength) of these membranes much exceeds the value typical of single-layered samples. The anionic conductivity of three-layered ceramics is studied by the impedance spectroscopy in the frequency range from 1Hz to 1 MHz. Membrane-electrode assemblies for SOFCs are fabricated and their electrochemical properties are studied under the conditions of fuel cell operation.