A micromodule, the size of 0.2 x 1 x 3 cm (similar to 0.6 cm(3)) was fabricated using three micro-solid oxide fuel cell (SOFC) bundles which consist of anode-supported microtubular SOFCs of 0.8 mm diameter and porous cathode matrices. The module was designed to apply to small-sized power sources at a low operating temperature under 600 degrees C. The open-circuit voltage of the module depended upon the operating temperatures, the lower for higher temperature due to the use of a ceria-based electrolyte. Maximum power outputs of the module were 0.5, 0.9, and 1.4 W at 450, 500. and 550 degrees C operating temperatures, respectively, where the air was applied only by natural convection. As a result, the performance of the module turned out to be over 2 W per cm(3) at 550 degrees C operating temperature. The results also showed a strong influence of the fuel flow rate; the higher rate led to an increased performance due to improved gas transport. (C) 2008 The Electrochemical Society.