We developed a multi-layered LSCF/GDC/ScSZ/GDC/LSCF membrane reactor for NO decomposition, and its electrochemical properties and NO decomposition behaviors were investigated. A GDC buffer layer was able to prevent the harmful interfacial reaction between LSCF and ScSZ, mainly, strontium zirconate, which was observed in LSCF/ScSZ/LSCF membrane reactor. As a result, the electrode polarization resistance of the membrane reactor was significantly decreased in the multi-layered membrane reactor with the GDC buffer layer between the ScSZ electrolyte and LSCF electrode. From SEM observations, it was found that the GDC buffer layer deposited by a pulsed-laser deposition (PLD) process, was dense and showed homogeneous microstructure. Constructing the multi-layered membrane reactor could considerably reduce the consuming electrical power for NO decomposition.