Vehicle underbody structure

At the underside of a vehicle body (10), a fuel tank (18) and an exhaust muffler (16) are disposed alongside of each other along a vehicle body longitudinal direction, with a drive shaft being disposed between the fuel tank and the exhaust muffler. The front and rear of the fuel tank (18) are attached with tank bands to two cross members (20,22). The exhaust muffler (16) is attached to the two cross members (20,22) via rubber supports (28). Because the exhaust muffler (16) and the fuel tank (18) are attached to common cross members (20,22), the noise vibration characteristics of the vehicle body are improved while suppressing an increase in the weight of the vehicle body.