To provide a printed circuit board and a circuit device for reducing warp and weight of the board and improving heat radiating property.

The printed circuit board includes a flat circuit board material 11, a through-hole 16 formed to the circuit board material 11, a copper chip 17 as a heat conductive member provided within the through-hole 16, wiring patterns 12, 13 formed on both surfaces of the circuit board material 11, and a heat generating element 14 mounted on the wiring pattern 12 at the front surface side as the one surface of the circuit board material 11. In the wiring pattern 13 at the rear surface side as the other surface of the circuit board material 11, a part provided opposed to the heat generating element 14 is formed thicker than the other part and the copper chip 17 is thermally connected to both heat generating element 14 and the thick wiring pattern 13a.