Fuel cells are electro-chemical reactors which realize the direct conversion of the chemical energy of reactants to electrical energy, with high efficiency and high environmental compatibility. Direct methanol fuel cell (DMFC) is considered as a highly promising power source. It has a number of advantages such as a liquid fuel, quick refueling, low cost of methanol and the compact cell, design making it suitable for various potential applications including stationary and portable applications. The goal of this study is to model the overall performance of the DMFC system and also, investigate the anode, the cathode of a DMFC theoretically to obtain a set of parameters for a DMFC model. This study has been concerned with an exergetic analysis of the fuel cell system from investigating the performance with respect to operating conditions such as concentration of methanol and temperature. Exergy analysis appears to be a potential for system design, analysis, and process evaluation and improvement also exergy is a tool for tracing the useful portion of the energy flowing through a system. Energy analysis alone can often be misleading, as energy can be transformed to many forms with different levels of quality. An exergetic analysis of a system helps identify primary sources of loss and provides a more accurate picture of the performance relative to the theoretical ideal.