However, there are several issues in commercialization of PEMFC [20]. Among them, one of the most important issues is water management problem, which is mainly managed two parts including both the water content of humidified gas and the electro-migration water content. The water content of the humidified gas is affected deeply by relative humidity (RH). Hence, many researchers took active steps to research the effects of RH on the performance of PEMFC and improve the performance of PEMFC.