A solid oxide fuel cell (SOFCs) is one of the fuel cells, and co-tape casting process has been widely used to fabricate unit cells. In this study, each step of co-tape casting process and corresponding process conditions were studied to fabricate crackand warp-free large-area unit cells. Thermal decomposition rate, flexural strength, and shrinkage behavior were measured by thermo-gravimetric analysis, three point flexural test, and thermomechanical analysis, respectively. As a result, heat treatment steps at 250 °C and 350 °C were adopted. The anode support layer composition with coarse NiO and pore former mixture of 5 wt% of carbon black and graphite was applied to obtain the highest flexural strength. The co-sintering temperature was determined at 1250 °C to have the smallest shrinkage rate difference between anode and electrolyte. Then, a warp-free large-area unit cell with a diameter of 50 mm and open circuit voltage of 1.05V was fabricated.