To provide a traveling mechanism capable of stably self-supporting a mobile element, and also simply moving the element not only on a flat plane but also on a stepped ground.
This traveling mechanism comprises a wheel 10 installed to a mobile element 1 traveling on the ground and projectably installed from the surface of the mobile element 1, and a projecting means 20 for projecting the wheel 10. The projecting means 20 is equipped with a fixing means 40 for fixing and releasing the movement of an axle part 21 relative to the mobile element 1 at an accommodation position and a projecting position. The wheel 10 is constituted of a rotor 12 having at least three peaks at a position relatively symmetrical to each other with an axle 22 of the axle part 21 as a center, and rollers 13 rotatably mounted to the peaks of the rotor 12, respectively. The rotor 12 is equipped with a slidable guide face 12s with small friction resistance which is recessed like an arc shape in its central direction between the adjacent peaks on its outer periphery.