The effect of phosphorus ions on the proton conductivity was examined for the sol-gel-derived glasses. The porous glasses were prepared through hydrolysis of PO(OCH3)(3) and Si(OC2H5)(4), in which the phosphorus ions consisted of the POH bonds and were dissolved into the silica matrix without any P-O-Si bond. The electrical conductivity increased in a humid atmosphere and reached similar to 30 mS/cm at 50 degreesC under 70% RH. High conductivity is achieved by both the POH bonds and the molecular water bonded to the POH bonds. The conductivity increased with a change in humidity from 40% to 80% RH. The phosphorus ions were selectively dissolved in water, resulting in a lower conductivity.