A method for manufacturing a monoblock brake caliper, the method comprising: a first step of forming a brake hydraulic line formed as a U-shaped pipe; a second step of disposing the brake hydraulic line inside a die where a caliper body including an arcuate section formed in an arc shape so as 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 is to be formed, the brake hydraulic line being formed so as to be inserted into the side section of the to-be-formed caliper body along the longitudinal direction of the side section; a third step of disposing a metal core in the die in such a manner as to be mounted on the inner side of each of the side sections 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; a step of filling a filling material in the brake hydraulic line either before the second step or between the second step and the third step; a fourth step of casting the caliper body to allow the brake hydraulic line disposed in the die to be inserted into the caliper body and allow a cylinder to which the piston is to be inserted to be formed by the metal core; a step of removing the filling material from the brake hydraulic line after the caliper body cast in the fourth step has been cured; a fifth step of removing the die and the metal core from the cast caliper body; a sixth step of subjecting an adjoining portion between the cylinder formed by the removed metal core and the brake hydraulic line to a cutting process so that the brake hydraulic line and the cylinder fluidically communicate with each other; and a step of inserting the piston into the cylinder, and coupling an air bleeder to each of both ends of the brake hydraulic line to bleed air present inside the brake hydraulic line during the supply of a brake oil to the inside of the brake hydraulic line, wherein the filling material is a metal filling material taking the shape of a bead which is easy to remove from the brake hydraulic line, the heat transfer coefficient of the brake hydraulic line is larger than that of the caliper body, and the brake hydraulic line comprises a metal coating layer formed on the outer surface thereof, the metal coating layer having a heat transfer coefficient larger than that of the brake hydraulic line. a first step of forming a brake hydraulic line formed as a U-shaped pipe; a second step of disposing the brake hydraulic line inside a die where a caliper body including an arcuate section formed in an arc shape so as 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 is to be formed, the brake hydraulic line being formed so as to be inserted into the side section of the to-be-formed caliper body along the longitudinal direction of the side section; a third step of disposing a metal core in the die in such a manner as to be mounted on the inner side of each of the side sections 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; a step of filling a filling material in the brake hydraulic line either before the second step or between the second step and the third step; a fourth step of casting the caliper body to allow the brake hydraulic line disposed in the die to be inserted into the caliper body and allow a cylinder to which the piston is to be inserted to be formed by the metal core; a step of removing the filling material from the brake hydraulic line after the caliper body cast in the fourth step has been cured; a fifth step of removing the die and the metal core from the cast caliper body; a sixth step of subjecting an adjoining portion between the cylinder formed by the removed metal core and the brake hydraulic line to a cutting process so that the brake hydraulic line and the cylinder fluidically communicate with each other; and a step of inserting the piston into the cylinder, and coupling an air bleeder to each of both ends of the brake hydraulic line to bleed air present inside the brake hydraulic line during the supply of a brake oil to the inside of the brake hydraulic line, wherein the filling material is a metal filling material taking the shape of a bead which is easy to remove from the brake hydraulic line, the heat transfer coefficient of the brake hydraulic line is larger than that of the caliper body, and the brake hydraulic line comprises a metal coating layer formed on the outer surface thereof, the metal coating layer having a heat transfer coefficient larger than that of the brake hydraulic line.