PURPOSE: To provide a vehicular fuel tank by which an oil transfer pump can be operated efficiently in transferring fuel to a main tank from a sub tank in the vehicular fuel tank having two tanks of the main tank and the sub tank.

CONSTITUTION: A full tank sensor 20 is arranged in a main tank 10, and this detects that the main tank 10 is put in a full condition. Operation of an oil transfer pump 54 is stopped by detecting this full condition, and oil transfer is stopped. Thereby, since there is no need to arrange a pipe to circulate excessive fuel, useless pump operation can be avoided. An empty sensor 42 is arranged in a sub tank 40, and the operation of the oil transfer pump 54 is stopped by detecting this empty condition, and the oil transfer is stopped. Thereby, since the oil transfer pump 54 runs idle, this can be prevented from running into trouble.