Abstract: The purpose of the present invention is to make supply of fuel to a fuel tank easy without making the fuel tank interfere with a drive shaft or a front wheel drive shaft and without lowering minimum ground clearance of a traveling vehicle. A fuel tank 12 is disposed between an engine 5 and a seat 7 and below a steering wheel 6, and a groove 12c is provided longitudinally at the substantial lateral center of the fuel tank 12. A power steering valve 24 is attached to the lower portion of the steering wheel 6, and grooves 12L and 12R in which hydraulic pipings 32 and 33 connected to the power steering valve 24 are arranged is formed in the fuel tank 12.