A 6-cell silicon-based micro direct methanol fuel cell (DMFC) stack utilized the serial flow path design was developed. The effect of the structure of flow path on the performance of the stack was investigated using polarization characterization and electrochemical impedance analysis. Further, the voltage distribution for individual cells under different current density was discussed. The results indicated that the DMFC stack with the serial flow path design exhibited better performance than that utilized the parallel flow path due to uniform mass transfer of methanol as a result of the use of the serial flow path. Such a DMFC stack generates a peak output power of ca. 187mW, corresponding to an average power density of ca. 21.7 mWcm-2, and exhibits a steady-state power output for more than 100h. Copyright (c) 2011 John Wiley & Sons, Ltd.