This paper presents a comparision between two controllers for Proton Exchange Membrane Fuel Cell PEMFC power system. The aim of this work is to keep the PEMFC working at its MPP by acting on the DC/DC converter, and ensure an adequate robustness against load and inputs variations. Conventional controller PI and backstepping technique are applied to the DC/DC boost converter. The stability of the backstepping is demonstrated by means of Lyapunov analysis. The model and the controllers are implemented in the MATLAB and SIMULINK environment. Simulation results indicate that the aim of this work is achieved using the backstepping algorithm.