The simulation and implementation of a sliding mode controller of DC-DC boost converter is presented in this work. The proposed control scheme was shown to be robust with respect to load and supply parameter step variations. The simulation results show the validity of the sliding mode controlled boost converter model and the robustness of this control technique against changes in the load or variations in the input voltage. Therefore the system achieves a robust output voltage against load disturbances and input voltage variations to guarantee the output voltage to feed the load without instability. The approach has several advantages such as stability even for large supply and load variations, robustness and good dynamic behavior. This method is applied to the control of an energy storage system based on supercapacitors technology in order to regulate the output voltage.