A method for manufacturing a double-sided circuit board includes preparing a substrate having the first and second surfaces, forming a first hole having a first opening with a diameter R1 on the first surface of the substrate, forming a second hole having a second opening with a diameter R2 on the second surface of the substrate, forming a third hole having a diameter smaller than R1 and/or R2 and connecting the first and second holes such that a penetrating hole formed of the first hole, the second hole and the third hole is formed in the substrate, forming a first conductive circuit on the first surface of the substrate, forming a second conductive circuit on the second surface of the substrate, and filling the penetrating hole with conductive material such that a through-hole conductor electrically connecting the first conductive circuit and the second conductive circuit is formed.