The control unit obtains an inclination assist value by correcting the assist value when a road surface is inclined in a left-right direction of the seat and performs a downhill turning preventing operation of causing the wheelchair body to travel straight by applying the right auxiliary power and the left auxiliary power corresponding to the inclination assist value； and adjusts the right auxiliary power and the left auxiliary power by correcting the inclination assist value according to a hand rim operation of the user to operate at least one of the right hand rim and the left hand rim in the downhill turning preventing operation.
