A small vehicle mounted with a fuel battery employs a fan that outputs a satisfactory amount of air with small power consumption. An exhaust duct reduces pressure loss and airflow resistance. Hydrogen purged from the fuel battery is discharged out of the vehicle along with water through the exhaust duct. A fan box has a fan for introducing air into the fuel battery mounted on a frame constituting vehicle body. After cooling the fuel battery, air is exhausted out of the vehicle. The exhaust duct includes two parts; i.e., a first exhaust duct connected to the rear side of the fan box for introducing the air after cooling of the fuel battery; and a second exhaust duct connected to the rear side of the first exhaust duct for exhausting the air flowing thereinto from the first exhaust duct out of the vehicle body.