A fast-proton-conducting porous tubular glass electrolyte was prepared by surface modification of glass, and the direct methanol fuel cell performance of the glass electrolyte was measured. The glass electrolyte showed very low methanol permeability of 2.1 x 10(-7) cm(2)s(-1) compared with the polymer electrolyte Nafion (R) (2.3 x 10(-6) cm(2) s(-1)). An open-circuit voltage of approximately 0.7 V was obtained at room temperature, which corresponds to 15 V when the tubes are stacked in a 6.5 cm(3) portable cell.