To provide a wheelchair foldable without dismounting a step ascending/descending device for ascending/descending steps and going over a groove part mounted on the wheelchair.

In the step ascending/descending device, the lower ends of two levers 8 and 15 whose upper ends are engaged with the wheelchair 1 rotatably in the front/rear and left/right directions are attached with screws to fixed blocks 2 and 3 integrally fixed to left and right leg frames 1a and 1b in such a way that the levers 8 and 15 can be rotated in left and right directions. In addition, an arc-shaped arm 12 with a larger radius of rotation than a rear wheel 13 (Figure 5) is integrally fixed to the lower end of one of the levers. Therefore, the wheelchair 1 can be folded with the step ascending/descending device mounted on the wheelchair, so that the time and effort in attaching/ detaching the device can be eliminated.