To reduce the height above the ground of the floor surface of a carbody as much as possible by arranging an air spring, a lower radius rod, an upper radius rod and a shock absorber inside the tire house outside a side rail entirely and arranging a lateral rod more downward than the past.

In a wheel suspending type suspension, an air spring 8, a lower radius rod 10, an upper radius rod 11 and a shock absorber 16 are entirely arranged outside a side rail 6 and inside a tire house 4. As a lateral rod 14 is arranged more downward than the past, the hight above a ground of the floor surface of the floor part 5 of a carbody 3 can be lowered. As the floor height above the ground of the carbody can be reduced without the follow of a cost up, the get on/off property of an omnibus on a regular route can be improved without spoiling the strong point of a low price.