A voltage conversion apparatus is disclosed in which a current passes through first and second loop circuits alternately in accordance with ON/OFF operation of a first switching element provided in the first circuit. The direction of a magnetic field through the first loop circuit formed at the ON operation is the same as a direction of a magnetic field through the second loop circuit formed at the OFF operation. The first loop circuit and the second loop circuit are provided on opposite sides of a printed circuit board, respectively, in such a manner that the first loop circuit and the second loop circuit are opposed to each other. A heat sink is provided on a surface of the printed circuit board. A solid pattern of a metal material is provided on an inner layer of the printed circuit board to be connected to the heat sink via a through hole.