A printed circuit board and manufacturing method thereof are disclosed. A printed circuit board composed of an insulation substrate, which includes an insulation layer, a circuit pattern formed on one side of the insulation layer, and an interlayer passage joined to the insulation layer and configured to electrically connect with the circuit pattern, and a heat-release layer, which is stacked on the other side of the insulation layer to be stacked on the insulation substrate, can provide a high heat-releasing effect and high bending strength, by means of inner layers or ground layers formed by the heat-release layers.