Proton exchange membrane (PEM) fuel cell has become one of the vital areas of research as an alternative power source in automotive as well as an emergency power supply. In this paper, an empirical model of the air breathing fuel cell (ABFC) is proposed to investigate its polarization characteristics, which are useful to analyze the real time system behavior at various operating states. The mathematical model is built in MATLAB/Simulink environment and the same is experimentally validated at various operating conditions and a reasonably good match is obtained between simulated and experimental results.