An ABS hydraulic unit that performs antilock brake control of a motorcycle, the ABS hydraulic unit comprising: a main housing that has at least part of a hydraulic circuit for controlling the pressure of brake fluid formed inside and is equipped with a mounting portion for mounting a brake lever of the motorcycle and an attachment portion having at least part of a side surface of a through hole formed along a first direction, the through hole being for attaching the ABS hydraulic unit to a handlebar of the motorcycle, wherein the hydraulic circuit comprises an inlet valve, a pressure reducing valve, an accumulator and a hydraulic plunger pump inside the main housing, wherein a suction port of the hydraulic pump is connected via a check valve to the accumulator and the pressure reducing valve; a master cylinder that has a piston portion that moves in conjunction with the brake lever, the master cylinder being for increasing, with the movement of the piston portion, the pressure of the brake fluid inside the hydraulic circuit; a motor that drives the hydraulic plunger pump mounted to the main housing; and a reservoir tank connected hydraulically to the master cylinder; wherein a piston insertion hole extending in the moving direction of the piston portion is formed in the main housing along a second direction that intersects the first direction, characterized in that the second direction is not orthogonal to the first direction, the motor is mounted to an upper surface of the main housing opposite to a lower surface with the ABS hydraulic unit attached to the handlebar, and the main housing has a side surface located between the brake lever mounting portion and the through hole on which a reservoir connection port is formed and to which the reservoir tank is connected in parallel to the motor, such that when the ABS hydraulic unit has been attached to the handlebar of the motorcycle, the reservoir tank is located between the mounted brake lever and the handlebar. a main housing that has at least part of a hydraulic circuit for controlling the pressure of brake fluid formed inside and is equipped with a mounting portion for mounting a brake lever of the motorcycle and an attachment portion having at least part of a side surface of a through hole formed along a first direction, the through hole being for attaching the ABS hydraulic unit to a handlebar of the motorcycle, wherein the hydraulic circuit comprises an inlet valve, a pressure reducing valve, an accumulator and a hydraulic plunger pump inside the main housing, wherein a suction port of the hydraulic pump is connected via a check valve to the accumulator and the pressure reducing valve; a master cylinder that has a piston portion that moves in conjunction with the brake lever, the master cylinder being for increasing, with the movement of the piston portion, the pressure of the brake fluid inside the hydraulic circuit; a motor that drives the hydraulic plunger pump mounted to the main housing; and a reservoir tank connected hydraulically to the master cylinder; wherein a piston insertion hole extending in the moving direction of the piston portion is formed in the main housing along a second direction that intersects the first direction,