To provide a fuel tank delaying timing of immersion in liquid of a re-circulation tube and further delaying liquid level rising speed in the re-circulation tube.

In the fuel tank, a partitioned space S communicated with the inside is formed on a tank body 2, one end of the re-circulation tube 7 is opened into an oil feed port 4, i.e., an oil feed nozzle insertion part and the other end is opened into the partitioned space S. A communication window W communicated with the inside of the tank body 2 is formed at a high position on the partitioned space S and an orifice O for restricting passing of the oil is formed at a low position.