To determine the stop of a vehicle at an uphill gradient by using a simple logic with little operation loading.

A difference P between braking force P1 at stopping the vehicle and braking force P2 at a time before a set time Tf is compared with a braking force value Px as a criterion when determining that a road surface is a uphill gradient. During deceleration and stop at the uphill gradient, the gravity of the vehicle forces the deceleration, and so a driver operates the vehicle to weaken braking force once right before the stop and grant great braking force again at the stop. In this case, there is a big braking force difference between a time right before the stop and a time at the stop, therefore permitting the uphill gradient to be determined only by detecting the braking force before and after the set time, as mentioned above.