PURPOSE: To travel over a surface for traveling, and simply ride across a step in particular when the device is driven by resting driver's own self over the surface for traveling.

CONSTITUTION: A plurality of operating shafts 2 are arranged so as to be movably mounted along the advancing or retreating direction for traveling, the axial directions of the respective operating shafts 2 are made different in the eccentric direction, however these shafts are made identical in an eccentric angle in the advancing or retreating direction, and each overlay condition is formed between the respective operating shafts 2, so that a plurality of advancing or retreating pieces 4 are mounted so as to be combined with one after another via eccentric discs 3 fixed onto the respective operating shafts 2. When any operating shaft 2 is to be driven by a drive source 5, let the lower contact periphery of each advancing or retreating piece 4 be moved up and down, moved to advance or retreat in a rapid succession one after another, and the lower contact periphery of each advancing or retreating piece 4 is rested over the surface for traveling so as to be transferred over the surface for traveling. Besides, a ride-across section is integrally formed in such a way that the starting end or terminal end of each advancing or retreating piece 4 is in a bent shape upward as vied from the side, and a non-slip means is formed at the lower contact periphery.