FUEL CELL SYSTEM

The present disclosure relates to a fuel cell system including a fuel cell stack, a humidifier configured to humidify air, which is to be supplied to the fuel cell stack, by means of moist air discharged from the fuel cell stack, a cleaning water supply line connected to the humidifier and configured to selectively supply cleaning water to the humidifier, and a cleaning water discharge line connected to the humidifier and configured to discharge the cleaning water to the outside of the humidifier, thereby obtaining an advantageous effect of improving durability and stability.