PURPOSE: To simplify manufacture of a circuit board with no need of preparing a die or the like by spraying a molten metal into the inside of a cavity of a metal mold to form a circuit while forming a resin mold layer on the cavity inside including an outside surface of the obtain circuit and thereafter removing the metal mold.

CONSTITUTION: A molten metal 7 is sprayed into the cavity inside 5a of a metal 5 by spraying to form circuit 7 and 7. In this case, for making it easy to form the circuit 7, for instance, a mask mold 6, whereon a mold releasing member R is formed, is formed on the cavity inside 5a. Later, plastic is molded on the obtained circuit pattern P to form a mold layer 6 followed by forming a solid mold wiring body M by removing the metal mold 5. Thereby, formation of a circuit pattern makes no trouble while facilitating formation of a solid wiring.