The fuel cell is a complex system an energy converter in which converts the chemical energy contained in hydrogen into electrical energy and heat. It is composed of several components: end plate, bipolar plates, gas diffusion layers (GDL) and membrane electrode assemblies (MEA). A fuel cell looks like a complex multi-physical system (mechanical, electrochemical, thermal and fluidic) where the performance could be influenced by a large number of uncertain mechanical parameters (temperature, clamping force), design parameters (dimensions of each component) and material parameters (properties of each component). All these parameters, especially the clamping force, can impact the assembly phase of the components and particularly the contact pressure at the interface of each component. A significant clamping force can generate high mechanical strain and stress in the membrane and the GDL and affect the distribution of contact pressure, the pore shape under the channels, the contact resistance and the fuel cell performance. On the other hand, a low clamping force could also cause a gas leakage between components therefore the contact resistance and the performance of the fuel cell. In this paper, 2D parametric finite element model is proposed to study the fuel cell performance. The repartition of contact pressure under isothermal mechanical loading in order to optimize the behavior of the fuel cell is discuss numerically. The influence of different design and operational parameters: size of pores in the GDL, thickness of the GDL and the bending radius of the bipolar plate was carried through an experimental plan.