An open cabin vehicle is equipped with a fuel cell unit having a hydrogen tank for storing hydrogen to be used as fuel and has a simple structure. An upper end of each of a hydrogen tank, a fuel cell stack, and a hydrogen supply pipe is located farther upward than a floor in a state in which the hydrogen tank, the fuel cell stack, and the hydrogen supply pipe are disposed in a fuel-cell-unit arrangement space which is provided below a space being present farther backward than at least a part of the floor in a vehicle-body inner space, and which borders the vehicle-body inner space, thereby being connected to a vehicle-body outer space which is a space around the open cabin vehicle, via the vehicle-body inner space.