A direct methanol fuel cell (DMFC) was operated at different phases of methanol feeding, i.e., a liquid phase, a gas phase with 90% relative humidity (RH) and a gas-liquid mixed two-phase with 130% RH, at 353K and the atmospheric pressure, and the i-V performances of the cell were compared. For the gas phase flow, the ohmic cell resistance became larger than that of the gas flow, suggesting a deficiency in the water content of the membrane. For the liquid phase and the two-phase flows, the same performance was obtained. Also, the overvoltage characteristic of the liquid phase feed was very similar to that of the gas phase when the methanol activities were almost the same. These findings suggested that the anodic overvoltage and the reaction mechanism are not affected by the state of the feed of methanol as long as the methanol activity is the same. Some difference was found in fluctuation characteristics, the frequency and the amplitude, of current density at a constant cell voltage among those states of the feed phase. This was attributed to the effect of mass transfer of CO2.