A fuel cell system including an exhaust merging unit at which a cathode exhaust fluid containing water discharged from a cathode of a fuel cell stack merges with an anode exhaust fluid containing water discharged from an anode of the fuel cell stack, wherein the exhaust merging unit includes a cathode exhaust outlet for discharging the cathode exhaust fluid, an anode exhaust outlet for discharging the anode exhaust fluid, and a partition separating the cathode exhaust outlet and the anode exhaust outlet on an upstream side of a merging section at which the cathode exhaust outlet and the anode exhaust outlet merge.