Solid oxide electrolyzer cells consisting of scandia-stabilized zirconia (ScSZ) electrolyte, Ni-yttria-stabilized zirconia (YSZ), and lanthanum strontium ferrite (LSCF)-gadolinia-doped ceria (GDC) were fabricated, and their performance in high-temperature steam electrolysis combined with methane partial oxidation was investigated. The voltage of the electrolyzer cell operated with methane/steam input was significantly reduced compared to that of the cell with air/steam input. The hydrogen production rates at 1.3 V (850 degrees C) were 4.53 and 1.74 sccm for the electrolyzer cell with methane/steam and air/steam inputs, respectively. On-line gas chromatography analysis confirmed the production of hydrogen and carbon monoxide in the anode side, indicating that methane partial oxidation occurred at the anode side.