In a vehicle brake device, a port is provided at a hydraulic chamber of a master cylinder and communicates with a reservoir tank. A piston movable in the hydraulic chamber for closing the port is provided with at least one piston-side port that faces on the port when at a first position. When a brake pedal is stepped on from a retracted state to move the piston from the first position to a second position spaced from the first position by a predetermined distance, the hydraulic chamber is blocked from the communication with the reservoir tank. The at least one piston-side port is provided therein with an orifice, so that the hydraulic pressure in the hydraulic chamber is raised at the time of a quick stepping of the brake pedal but is allowed to flow to the reservoir tank without being raised at the time of a non-quick stepping.