Abstract: This study evaluates the parameters that are associated with a combustion process of a Proton Exchange Membrane (PEM) fuel cell at various combustion conditions. Combustion parameters such as adiabatic flame temperature, air-fuel ratio, and fraction of water that condenses at 25 C and 1 atm, are considered in the analysis, which is performed at a theoretical air ratio ranging from 100 to 300% (from 0 to 200% excess air). Furthermore, exergy destruction associated with the combustion process was evaluated at each specified condition. The calculated results illustrated that the adiabatic flame temperature reached a maximum value of 2,526 K at 100% theoretical air and then reduced to 1,270 K at a theoretical air of 300%. Conversely, exergy destruction was evaluated to be 53,236 and 96,949 kJ kmol ¹ at 100 and 300% of theoretical air, respectively.