Disclosed is a monoblock brake caliper comprising a caliper body including an arcuate section in an arc shape to partially surround a brake disc, and a side section formed at both sides of the arcuate section and positioned in close proximity to both sides of the brake disc; a brake hydraulic line disposed inside the caliper body and configured to be insert-cast during the casting of the caliper body so as to be formed as a U-shaped pipe; and a metal core disposed on the inner side of the side section of the caliper body so as to be positioned adjoining the brake hydraulic line at a portion where a piston is to be disposed during the casting of the caliper body so that the metal core is removed from the caliper body after the casting of the caliper body to form a cylinder in the caliper body.