PURPOSE: To permit the up and down traveling of a crawler type traveling vehicle on steps smoothly and safely by engaging a nearly inversed triangular crawler belt to a vehicle.

CONSTITUTION: By driving sprockets 4a and 4b for driving, crawler belts 9 and 10 are moved through sprockets 5a and 5b for guiding and guiders 8a and 8b for crawlers, and thereby a traveling vehicle is run on the flat ground forward and backward. Also, at the beginning of going up the steps 11, the traveling vehicle can go up as such by the inclined straight line portions of the crawler belts 9 and 10. In particular, since the crawler teeth 9a and 10a of the crawler belts 9 and 10 can run while being coupled with a projection 11a provided to the end edge of the steps 11, safeness and reliability of the running can be raised.