A wheel cylinder receives operating fluid supplied from a master cylinder or an accumulator and operates a brake provided on each wheel of a vehicle. A valve control portion operates a master cutoff valve and a pressure increase valve in response to an operation of a brake pedal. When the brake pedal is operated, an operation timing instructing portion first instructs the valve control portion to operate the master cutoff valve. A voltage recovery characteristics measuring portion measures a voltage recovery time that it takes for the voltage of a power supply to recover to a predetermined level from a temporary drop due to operation of the master cutoff valve. Then after the voltage recovery time has passed after the master cutoff valve was operated, the operation timing instructing device instructs the valve control portion to operate the pressure increase valve.