Proton Exchange Membrane Fuel Cell (PEMFC) appears to be a promising technology to take up the challenges of energy transition, therefore it appears necessary to optimize the systems to use the right amount of raw materials. In our study, we have addressed the mechanical aspects and their impacts on performance of it. More specifically, the main objective of the proposed work is to understand the influence of fuel cell core design and mechanical properties on electrical resistances of internal system contacts. Indeed, electrical contact resistances are one of the important sources of losses and therefore require special attention. To achieve this, a Design of Experiments (DoE) associated with a Finite Element Model was used in order to obtain the influence of geometrical and mechanical parameters on the performance of PEMFC, where each thickness of each layer and the constitute constitutive law of the Gas Layer Diffusion GDL were focused on.