A method of estimating a lifespan of a fuel cell including a cathode and an anode which contain catalysts and an electrolyte membrane interposed between the anode and the cathode. A cyclic potential with a voltage ranging from a low voltage to a voltage greater than oxidation voltages of the catalysts is applied between the anode and the cathode and fuel cell performance is measured initially and after a predetermined number of cycles. The lifespan of the fuel cell may estimated based on degradation of cell performance after the predetermined number of cycles, based on CV curves obtained during the cycling of the potential and/or a change in particle size of the catalysts after the predetermined number of cycles.