This paper describes a new type of miniature hydrogen electrode that is composed of a tubular polymer electrolyte and is suitable for use as the reference electrode in electrochemical measurements. The tubular hydrogen electrode was fabricated by supporting platinum black powder inside a perfluorinated polymer electrolyte tube and feeding hydrogen gas into the tube. It can be used as the reference electrode for electrochemical measurements both in acid electrolyte solutions and in a testing apparatus, for example, in polymer electrolyte fuel cells. The specific feature of the tubular hydrogen electrode is that it is so small that it can fit in microanalytical or electrochemical cell systems. The tubular hydrogen electrode can also work as both a counter electrode and a nonpolarizable reference electrode because of the very large specific surface area of the platinum particles deposited inside. This makes these tubular hydrogen electrodes usable in two-electrode cells, which is another advantage over conventional glass-type hydrogen reference electrodes. (c) 2005 The Electrochemical Society.