In the case that a vehicle 1 is making a reverse movement, a control section 4 sets a braking control operation distance according to an angle formed by the vehicle 1's proceeding direction and an extending direction of a road on which an approaching vehicle is traveling. With this, a braking control is implemented at a delayed timing in a scene where the following possibility is high: the driver wishes to end the reverse movement operation as early as possible when a space for allowing the approaching vehicle to pass by is not present at the back of the vehicle 1. Thereby, the cumbersomeness or discomfort which may be felt by the driver with respect to the braking control can be decreased.