To improve running stability in the advancing direction of a vehicle.

A wheelchair employs a ball transfer 1 instead of a front wheel and runs on a ground 9. The ball transfer 1 is relatively movable in a plane on the ground 9 and comprises a body 2, a large ball 5, a plurality of small balls 6, and a regulation member. The large ball 5 makes contact with the ground 9. The small ball 6 is moved along the outer peripheral surface of the large ball 5 as it is rotated according to rotation of the large ball 5, and the large ball 5 is supportable on the body 2. The diameter of the small ball 6 is smaller than that of the large ball 5. The regulation member regulates movement of a part of the small balls 6.