A
brake system of the present invention is a dual
braking system, which includes an ECU that controls parts for braking when a
brake pedal is operated, a main
brake that is controlled by ECU by locking a wheel disc for braking in normal braking, and a sub-brake that is mounted on the wheel disc and achieves sub-braking function to achieve emergency braking for safety by locking the wheel disc by control of ECU that has detects failure of main brake. Therefore, it is possible to improve safety by achieving emergency braking while achieving F-S (Fail-Safe), when the motor of main brake fails. Further, it is possible to also achieve stable FR (
Failure Rate) in an EWB or an EMB that is practically applied to a vehicle, as in a
hydraulic brake system, and to expedite common use of brake systems where a BBW (
Brake By Wire) technology, such as EMB and EWB, is applied.