A new porous glass electrolyte consisting of heteropolyacids, i.e., phosphotungstic acid (PWA) and phosphomolybdic acid, was investigated and was found to yield a remarkably high proton conductivity of 1.014 S cm(-1) at 30 degrees C and 85% relative humidity. This is the first time such a high proton conductivity value has been reported for a heteropolyacid glass membrane. The glass was applied as the electrolyte for an H(2)/O(2) fuel cell, and a maximum power density of 41.5 mW/cm(2) at 32 degrees C was attained using this new PWA-containing electrode.