Here, we report a chip-type module [size: 0.3x1x3 cm (similar to 1 cm(3))+fuel manifold] using micro-solid oxide fuel cell (SOFC) bundles which consist of anode-supported microtubular SOFCs with 2 mm diameter, porous cathode matrices, sealing layers, and interconnects. The module is a three-bundle stack with fuel manifolds and is designed to apply to small-sized power sources. The performance of the module was shown to be 2.85-2.6 V open-circuit voltage, with maximum power outputs of 0.91, 1.54, and 1.79 W at 450, 500, and 550 degrees C operating temperatures, respectively, where the air was applied only by natural convection. An increase of the fuel flow rate effectively improved the performance of the module due to an improvement of the gas transport process. The fuel utilization of the module was also estimated for the optimization of the module operating conditions, which was strongly influenced by the fuel flow rates and the operating temperatures. (C) 2008 The Electrochemical Society. [DOI: 10.1149/1.2990722] All rights reserved.