In a fuel cell system 20 mounted on a fuel cell vehicle of the invention, water separated by a gas-liquid separator 38 included in a hydrogen supply system and by a gas-liquid separator 48 included in an air supply discharge system 40 is temporarily accumulated in buffer tanks 62a through 62c, which are set inside a front fender or inside a front bumper of the vehicle. The accumulated water is released from water outlets 64b and 64c located forward and backward a front wheel of the vehicle having relatively little potential effects of vehicle wind or air flow caused by motion of the vehicle. For the purpose of reducing the potential effects of the vehicle wind on the released water, the fuel cell vehicle may have an air flow path that makes the released water flown obliquely backward the vehicle by the air flow or form an air curtain of exhaust gas or the air ahead of the released water. This arrangement effectively restricts the released water from being scattered by and swirled on the vehicle wind and thereby prevents potential troubles such that the released water is scattered on other vehicles running on the side and behind.