Provided is a wheel which is inexpensive, light, and sufficiently rigid. A wheel 6a includes an annular rim 60 to which a tire 6b is externally fitted, a hub 61 which is arranged at a center portion of the rim 60 and to which an axle is connected, and a disk 62 which is attached with the rim 60 at a periphery portion and which covers one side of the wheel 6a. The disk 62 includes a planar portion 62a and a first rib 62b provided at a surface of one side of the planar portion 62a and extending in the radial direction. The planar portion 62a is provided with a first groove 62d at a surface of the other side at a position corresponding to the first rib 62b.