Provided is a method of manufacturing a printed circuit board. In an embodiment, the method includes forming a prepreg layer via a reel method, forming a conductive film for forming a circuit pattern on at least one surface of the prepreg layer; and forming a predetermined circuit pattern on the conductive film. In an embodiment, the prepreg layer has a thickness of at most about 0.15 mm and contains a fiber material and a resin material. In an embodiment, the content of the resin material in the prepreg layer is about 70% or less by volume. In an embodiment, the prepreg layer is composed of at least one prepreg layer.