We have succeeded in fabricating a solid-oxide-electrolyte fuel cell, with the highest power-generation density, with a maximum single-cell-level density of 1550 mW/cm2. This cell was made by depositing a 10-mu-m thick 10 mol% (m/o) yttria stabilized zirconia (YSZ) electrolyte layer on a porous La(Sr)MnOx cathode tube using the electrochemical vapor deposition method and then making a Ru/YSZ cermet anode on top of it.