Gadolinia-doped ceria (GDC) buffer layers were synthesized by reactive magnetron sputtering under different total pressures and different thickness. All as-deposited and after an annealing treatment during two hours under air at 1000 °C coating presents a face centered cubic (f.c.c) structure of ceria with dense and adhesive morphology. The cell synthesized under 0.1 Pa and 0.57 µm present the best performances. (open-circuit voltage (OCV): 1.133 eV and power density: 1650 mW·cm−2 @ 800 mA·cm−2 at 790 °C).