A braking control apparatus comprising: a master cylinder, the master cylinder including: a first piston coupled to a brake pedal and configured to be displaced in response to a brake operation; a second piston movable in linkage with the first piston; a cylinder for housing the first piston and the second piston slidably in an axial direction; a first fluid pressure chamber defined by the first piston and the second piston, having a passage communicating with a reservoir tank for storing brake fluid, and configured to generate a fluid pressure when communication with the reservoir tank is blocked at displacement of the first piston by a first stroke; a second fluid pressure chamber defined by the second piston and a side wall of the cylinder, having a passage communicating with the reservoir tank, and configured to generate a fluid pressure when communication with the reservoir tank is blocked at displacement of the second piston by a second stroke; a first fluid pressure line connecting the first fluid pressure chamber to a wheel cylinder provided on a first wheel; and a second fluid pressure line connecting the second fluid pressure chamber to a wheel cylinder provided on a second wheel; and a stroke simulator configured to communicate with the fluid pressure chamber being subject to the smaller of the first stroke and the second stroke and configured to generate a reaction force in the brake pedal when the brake is operated, characterised in that the fluid pressure chamber to which the stroke simulator is connected when the brake pedal is operated generates a fluid pressure before the other fluid pressure chamber. a master cylinder, the master cylinder including: a first piston coupled to a brake pedal and configured to be displaced in response to a brake operation; a second piston movable in linkage with the first piston; a cylinder for housing the first piston and the second piston slidably in an axial direction; a first fluid pressure chamber defined by the first piston and the second piston, having a passage communicating with a reservoir tank for storing brake fluid, and configured to generate a fluid pressure when communication with the reservoir tank is blocked at displacement of the first piston by a first stroke; a second fluid pressure chamber defined by the second piston and a side wall of the cylinder, having a passage communicating with the reservoir tank, and configured to generate a fluid pressure when communication with the reservoir tank is blocked at displacement of the second piston by a second stroke; a first fluid pressure line connecting the first fluid pressure chamber to a wheel cylinder provided on a first wheel; and a second fluid pressure line connecting the second fluid pressure chamber to a wheel cylinder provided on a second wheel; and a first piston coupled to a brake pedal and configured to be displaced in response to a brake operation; a second piston movable in linkage with the first piston; a cylinder for housing the first piston and the second piston slidably in an axial direction; a first fluid pressure chamber defined by the first piston and the second piston, having a passage communicating with a reservoir tank for storing brake fluid, and configured to generate a fluid pressure when communication with the reservoir tank is blocked at displacement of the first piston by a first stroke; a second fluid pressure chamber defined by the second piston and a side wall of the cylinder, having a passage communicating with the reservoir tank, and configured to generate a fluid pressure when communication with the reservoir tank is blocked at displacement of the second piston by a second stroke; a first fluid pressure line connecting the first fluid pressure chamber to a wheel cylinder provided on a first wheel; and a second fluid pressure line connecting the second fluid pressure chamber to a wheel cylinder provided on a second wheel; and a stroke simulator configured to communicate with the fluid pressure chamber being subject to the smaller of the first stroke and the second stroke and configured to generate a reaction force in the brake pedal when the brake is operated, characterised in that the fluid pressure chamber to which the stroke simulator is connected when the brake pedal is operated generates a fluid pressure before the other fluid pressure chamber.