International audienceAvailable online xxx Keywords: Polymer Electrolyte Membrane Fuel Cell PEMFC fractional order model FC parameter identification Diagnosis a b s t r a c t The present paper addresses the important issue of monitoring the operating state of the Polymer Electrolyte Membrane Fuel Cell systems. The monitoring system takes a model based approach. Its originality lies in adopting a fuel cell fractional order impedance model which permits to provide a better insight into the fuel cell physical phenomena without increasing the number of parameters. This article first validates experimentally the accuracy of the suggested model, using a frequency identification method carried out by nonlinear optimization using single fuel cell e...