To provide technique for performing a collision prevention operation properly when the car is running at a speed equal to or less than a predetermined speed.

When an own vehicle is running at low speed and when degree of steering (magnitude of a steering angle ) by an operator is in a predetermined range, control command from a calculation processing part output to a brake control part for suppressing an automatic brake is released as exceptional case. Therefore when the own vehicle is running at low speed, the automatic brake is not suppressed by steering of a modified steering level, and the brake control part performs automatic brake properly.