The effect of the thickness of the gold, silver and cupper films on the electrical properties such as open circuit voltage (V-oc) and short circuit current (I-sc), in the direct hydrogen fuel cell, which uses water as a source of hydrogen, is studied by fabricating Metal/Porous Silicon/n-Silicon/Indium structures. The Porous Silicon (PS) layer on n-type (111) oriented silicon wafers were prepared by anodization. The thin films of Au or Ag or Cu with different thicknesses between 120 and 600 nm were deposited onto the PS surface by the electron-beam technique. The obtained results indicated that V-oc and I-sc, strongly depend on the Au, Ag and Cu layer thicknesses. The Au/PS/n-Si structure generated highest V-oc and I-sc values for all thicknesses of Au film. The best values of V-oc and I-sc were obtained at 325 nm as 0.89 V and 0.021 mA for Au, at 350 nm as 0.75 V and 0.017 mA for Ag, at 350 nm as 0.50 V and 0.010 mA, respectively. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.