To provide a wheel device for walking aid, which has a braking mechanism to be surely operated corresponding to the braking request of a user, and a self-walking supporting machine provided with the same device.

Concerning the wheel device for walking aid provided with a wheel 1, an axle for supporting the wheel through it and a braking means for braking the turn of the wheel, the braking means is provided with a braking ring 6 supported on the axle and rotated integrally with the wheel while having plural groove parts 8 of prescribed depth around the outer periphery thereof, a first braking pin 9 fitting the top end to the groove part, a first spring member 10 for energizing the first braking pin toward the outside of the wheel and securing a prescribed interval between the outer periphery of the braking ring and the top end of the first braking pin, a second spring member 12 abutted to the rear end of the first braking pin, a second braking pin 11 energized toward the outside of the wheel by the second spring member while having a prescribed interval to the rear end of the first braking pin, a cylinder member 15 for operating the second braking pin toward the wheel and a driving source for driving the cylinder member.