FUEL CELL SYSTEM

The present disclosure relates to a fuel cell system including a discharge line configured to discharge exhaust gas, which is discharged from a fuel cell stack, to the outside, and a pneumatic branch line having an outlet end connected to the discharge line, and an inlet end connected to a pneumatic supply unit configured to supply air to a pneumatic part of a mobility vehicle, the pneumatic branch line being configured to selectively supply the air from the pneumatic supply unit to the discharge line, thereby effectively reducing a hydrogen concentration in the exhaust gas discharged from the fuel cell stack.