Anode-supported flat tubular solid oxide fuel cell (SOFC) was investigated to increase the cell power density. The anode-supported flat tube was fabricated by extrusion process. The porosity and pore size of Ni/YSZ ($8mol\%$ yttria-stabilized zirconia) cermet anode were $50.6\%;and;0.23{mu}m$, respectively. The Ni particles in the anode were distributed uniformly and connected well to each other particles in the cermet anode. YSZ electrolyte layer and multilayered cathode composed of $LSM(La_{0.85}Sr_{0.15})_{0.9}MnO_3)/YSZ$ composite, LSM, and $LSCF(La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.7}O_3)$ were coated onto the anode substrate by slurry dip coating, subsequently. The anode-supported flat tubular cell showed a performance of $300mW/cm^2 (0.6V,; 500 mA/cm^2);at;500^{circ}C$. The electrochemical characteristics of the flat tubular cell were examined by ac impedance method and the humidified fuel enhanced the cell performance. Areal specific resistance of the LSM-coated SUS430 by slurry dipping process as metallic interconnect was $148m{Omega}cm^2;at;750^{circ}C$ and then decreased to $148m{Omega}cm^2$ after 450hr. On the other hand, the LSM-coated Fecralloy by slurry dipping process showed a high area specific resistance.