In the present work, we develop a dynamical model for single cell of the Proton Exchange Membrane Fuel Cell (PEMFC). The model studies the phenomena of charge and mass transport through the cell elements. It integrates also the electrical aspect related to reaction kinetics by proposing an electrical equivalent circuit of the cell. The influence of gas consumption and humidification rates on water diffusion and membrane humidity are considered. Simulation results are used to verify the model and to build an appropriate control of the membrane humidity. The control which is done by regulating the water mole fractions in gases aims to minimize energy losses. Simulation results show that the control proposed ensures an improvement in the dynamic electrical efficiency. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.