Fuel Cell (FC) is electrochemical systems capable to convert the oxygen and hydrogen chemical energy to electrical energy. FC is as a promising alternative due its suitable efficiency, low pollution to the environment, high reliability and durability and excellent dynamic response. In this study we have implemented simple PEMFC in GAMS environment considering its input hydrogen molar flow rate consumption. Then the impact of effective operational parameters is investigated on optimal operation and output power of PEMFC. This study can ensure PEMFC optimal operation and maximizing its generated power considering obtained results from modeling and different effects of each operational parameter.