Abstract: A circuit board using a heat radiating member that can cool an electronic component sufficiently without causing a substrate to break, increasing the total weight of the substrate, lowering the productivity, or increasing cost and device size. A circuit board has a substrate main body (4) having a wiring pattern (3) formed on a surface side, and a structure in which an LED module (1) is connected to the wiring pattern (3). The circuit board is characterized in that: a through hole (6) is provided in a portion of the substrate main body (4) so as to penetrate the substrate main body (4) from the surface side to a back side thereof; a heat radiating member (5) is provided on the back side of the substrate main body (4) so as to close one end of the through hole (6); and the LED module (1) is disposed in the through hole (6) so that the heat radiating member (5) and the LED module (1) are directly in contact with each other.