Fuel cell is an electrochemical system that converts chemical energy to electricity directly and without combustion. Due to various applications and high energy efficiency of fuel cells, these systems are known as one of the most popular energy conversion systems. So, optimization of fuel cell systems is considered and analyzed by many of scientists and researchers. Therefore, in this study a techno-economic model is developed. First we introduce the overview of the methodology of solving the optimization problem and then, using the equations presented in modeling sector and with considering temperature and pressure of the system, air and hydrogen stoichiometric ratio and current density, a model for a 50 kW fuel cell stack cost is developed. Finally, optimization of costs for constructing a 50 kW fuel cell stack including a fuel cell, air compressor, hydrogen storage tank and other components was implemented using genetic algorithm. Then, sensitivity analysis was performed on the parameters. Improving the objective function with changing these parameters is then discussed.