A vehicle brake apparatus comprising; a boosted hydraulic pressure chamber; a master cylinder comprising: a master piston of which back side faces the boosted hydraulic pressure chamber; and a casing accommodating the master piston in a slidable manner; a hydraulic pressure generating source; a reservoir; and a pressure regulating valve unit which regulates output hydraulic pressure of the hydraulic pressure generating source in response to an input of brake application effort from a brake operation member for application to the boosted hydraulic pressure chamber; wherein the master cylinder is connected to wheel brakes (BA, BB, BC, BD), the hydraulic pressure generating source is made up of only a pump, an accumulator is connected to the pump via an open-close-valve which is controlled by a control unit, and a supply port in the casing of the master cylinder communicating with the boosted hydraulic pressure chamber; wherein a discharge port of the pump is connected via a primary linear solenoid valve to a hydraulic pressure path connected to the supply port, the primary linear solenoid valve being part of the pressure regulating valve unit; a first hydraulic pressure sensor is connected to the hydraulic pressure path which is adapted to detect hydraulic pressure in the boosted hydraulic pressure chamber; a second hydraulic pressure sensor adapted to detect hydraulic pressure in the accumulator; and wherein the control unit controls the open-close-valve when the brakes are being applied to open or close so as to accumulate a hydraulic pressure to a preset pressure in the accumulator according to a detection value of the second hydraulic pressure sensor while causing the pump to operate while the primary linear solenoid valve is closed; and the control unit further controls the open-close-valve to open and the primary linear solenoid valve to close at an initial stage of the brake applying operation so as to accumulate said hydraulic pressure in the accumulator, thereafter to close the open-close-valve and then, still in the initial stage of the brake applying operation, when the first hydraulic pressure sensor detects that the hydraulic pressure in the boosted hydraulic pressure chamber has reached a predetermined value, to open again the open-close-valve and to open the primary linear solenoid valve, so as to supply said hydraulic pressure within the accumulator to the boosted hydraulic pressure chamber. a master piston of which back side faces the boosted hydraulic pressure chamber; and a casing accommodating the master piston in a slidable manner; a hydraulic pressure generating source; a reservoir; and a pressure regulating valve unit which regulates output hydraulic pressure of the hydraulic pressure generating source in response to an input of brake application effort from a brake operation member for application to the boosted hydraulic pressure chamber; wherein the master cylinder is connected to wheel brakes (BA, BB, BC, BD), the hydraulic pressure generating source is made up of only a pump, an accumulator is connected to the pump via an open-close-valve which is controlled by a control unit, and a supply port in the casing of the master cylinder communicating with the boosted hydraulic pressure chamber; wherein a discharge port of the pump is connected via a primary linear solenoid valve to a hydraulic pressure path connected to the supply port, the primary linear solenoid valve being part of the pressure regulating valve unit; a first hydraulic pressure sensor is connected to the hydraulic pressure path which is adapted to detect hydraulic pressure in the boosted hydraulic pressure chamber; a second hydraulic pressure sensor adapted to detect hydraulic pressure in the accumulator; and wherein the control unit controls the open-close-valve when the brakes are being applied to open or close so as to accumulate a hydraulic pressure to a preset pressure in the accumulator according to a detection value of the second hydraulic pressure sensor while causing the pump to operate while the primary linear solenoid valve is closed; and the control unit further controls the open-close-valve to open and the primary linear solenoid valve to close at an initial stage of the brake applying operation so as to accumulate said hydraulic pressure in the accumulator, thereafter to close the open-close-valve and then, still in the initial stage of the brake applying operation, when the first hydraulic pressure sensor detects that the hydraulic pressure in the boosted hydraulic pressure chamber has reached a predetermined value, to open again the open-close-valve and to open the primary linear solenoid valve, so as to supply said hydraulic pressure within the accumulator to the boosted hydraulic pressure chamber. the control unit further controls the open-close-valve to open and the primary linear solenoid valve to close at an initial stage of the brake applying operation so as to accumulate said hydraulic pressure in the accumulator, thereafter to close the open-close-valve and then, still in the initial stage of the brake applying operation, when the first hydraulic pressure sensor detects that the hydraulic pressure in the boosted hydraulic pressure chamber has reached a predetermined value, to open again the open-close-valve and to open the primary linear solenoid valve, so as to supply said hydraulic pressure within the accumulator to the boosted hydraulic pressure chamber.