Fixing structure and fixing method of circuit board with embedded electronic parts to cooler

In a fixing structure of a circuit board to a cooler, the circuit board includes a wiring part, electronic parts electrically connected to the wiring part and an insulating base material embedding the wiring part and the electronic parts therein. The insulating base material includes embedding portions in which the electronic parts are embedded and a bent portion having flexibility between the embedding portions. The cooler has fixing parts arranged in a first direction. The circuit board is fixed to the cooler while bending the bent portion. The bent portion is opposed to an end portion of one of the fixing parts, and each of the embedding portions is held between adjacent two fixing parts such that opposite surfaces of the embedding portion are closely in contact with surfaces of the adjacent two fixing parts.