PURPOSE: To make the whole of a device compact and light by comprising a pump for hydraulic pressure for a hydraulic brake booster, pumps for controlling an anti-skid brake and one motor for driving both the pumps.

CONSTITUTION: One pump P0 2 for hydraulic pressure for a hydraulic brake booster 3 and two pumps P1, P2 14 for controlling an anti-skid brake are driven by one motor 20. When lock of a wheel is detected, a controller rotates the motor 20, and while switches a solenoid valve corresponding to the locked wheel. The brake liquid of a wheel cylinder of the locked wheel is exhausted to a low pressure accumulator 13 to weaken the braking force of that wheel. The brake liquid exhausted to the low pressure accumulator 13 is sucked by the pumps P1, P2 14 to be supplied to a brake circuit (a). When lock of the wheel is cancelled, the braking hydraulic pressure is pressurized again.