In the butterfly-type molten carbonate fuel cell (MCFC), anode and cathode gases enter at the center of the gas channel and divide into two opposite directions in the gas channels, respectively. Mathematical modeling of the butterfly-type unit MCFC has been carried out and the results were compared with those of the co-flow type unit fuel cell, working at the same conditions and using the same amount of gases. In both the anode and the cathode gas channels, the local fuel conversions in the butterfly-type cell were slightly higher than those in the co-flow type fuel cell. Temperature distributions of the electrode-electrolyte plate in the butterfly-type cell were slightly lower than those of the co-flow type fuel cell. The more uniform temperature distributions could be obtained by using the butterfly-type fuel cell. However, distributions of current density and compositions become more nonuniform than those in the co-flow type fuel cell.