In this paper, we report the fabrication of a new miniature fuel cell (FC) for portable applications based on a Nafion(R)-filled porous silicon membrane. This technique allows to combine advantages of Nation(R) such as good proton conduction and silicon such as easy serial and parallel integration. Other advantages are the integration of gas feed and electrical contacts into the membrane etching process thanks to simple KOH wet etching processes and metal sputtering and the possibility of encapsulation. Moreover, with this technique we hope to reduce the lateral water diffusion through the membrane which is a problem with Nafion(D membranes. All the results have been obtained at room temperature and gas feed (H-2) is provided by the electrolysis of a NaOH solution. (C) 2004 Elsevier B.V. All rights reserved.