International audienceIn this paper, we present a new methodology for determining the complex impedance parameters for a Proton Exchange Membrane (PEM) Fuel Cell in order to have a general model for embedded diagnosis. The modelling of Fuel Cells is a very important phase because it contributes to a better understanding and representation of the internal phenomena in this type of generator. After obtaining the experimental results of the complex impedance using a realized test bench for Proton Exchange Membrane (PEM) Fuel Cell using an electrochemical method which is the electrochemical impedance spectroscopy (EIS), we treat these results with an identification algorithm based on least squares method in the objective to determine the variat...