A solid oxide fuel cell (SOFC) was fabricated by co-firing laminated sheets of air-electrode, electrolyte, and fuel-electrode and the influence of the physical characteristics of the air-electrode on the cell performance was studied. Tailoring the sintering shrinkage of green sheets to one another was found to be an important factor in fabricating a flat and fracture-free three-layer cell. Controlling the binder content in the fuel-electrode green sheet and calcination of La0.7Sr0.3MnO3 (LSM) powder were effective for tailoring the sintering shrinkage of green sheets. The performance of the co-fired three-layer cell was greatly influenced by the porosity of the air-electrode, and the maximum power density was attained at 70% of relative density, which is determined by the gas permeability and conductivity of air-electrode.