Braking discomfort applied to the driver is minimized. Provided are a brake operation amount section (26) capable of detecting a brake operation before a master cylinder hydraulic pressure is generated; an estimation section (28) for estimating the hydraulic pressure generation timing at which the master cylinder hydraulic pressure is generated, on the basis of detection information of the brake operation amount section (26); and a hydraulic pressure control section (29) for controlling the operation of an assist hydraulic pressure generation mechanism (D) by using the hydraulic pressure generation timing estimated by the estimation section (28) as a reference.