<p>This method for producing a circuit board has: a step for preparing a fiber-piece-containing paste; a step for producing a filtered recovered paste; a step for producing a reuse paste; a step for pasting a protective film; a step for forming a hole; and a step for filling the hole with the reuse paste. The method further has: a step for forming a protrusion comprising the reuse paste; a step for disposing and pressing a metal foil at both surfaces of a second pre-preg; a step for heating the second pre-preg, curing the second pre-preg and the reuse paste; and a step for processing the metal foil into a circuit pattern.</p>
