To provide a foldable fan-shaped wheel capable of traveling also on steps as a wheel for persons who have handicaps at legs or for transport articles.

This wheel has several flat bar-shaped arms arranged around a drive shaft in a fan shape at regular intervals. A spiral motion of an arm tip roller resulting from rotation of the drive shaft allows smooth plane-traveling and ascending and descending of steps, such as a staircase. In addition, the arms can be folded and housed in a line by rotating them around the shaft. By mounting these foldable wheels on a vehicle for persons having handicaps at legs or for article transportation as two pairs of left and right wheels in different pitches, an easy-to-carry staircase ascending and descending vehicle can be provided.