In this work, we will study and fabricate a new, simple and small-size hydrogen sensitive palladium (Pd) membrane/semiconductor Schottky diode sensor. Experimental results reveal that, during the hydride formation process, the forward- and reverse-biased currents are increased by the increase of hydrogen concentration. It also demonstrates that the Schottky barrier height is indeed decreased with increasing the hydrogen concentration. Therefore, the studied device can be used in fabricating a high-performance hydrogen sensitive sensor. (C) 2002 Elsevier Science B.V. All rights reserved.