This paper concerns with the study on the effect of hydrogen Purging period on the performance of PEMFC system. It is aimed to improve PEMFC performance to be a reliable power source for power supply unit. The membrane electrode assembly of a PEMFC (Proton Exchange Membrane Fuel Cell) has to be wet for the fuel cells to work efficiently. Despite many factors causing cell degradation and jeopardize the stack performance and attenuate the electrochemical reaction, this paper only focuses on an arrangement of hydrogen purging period to remove water droplets and residue of inert gas from the anode side of the fuel cell. Experiments show the stack performance as well as its efficiency at various purging periods at 100 W and 400 W loads.