Plural induction heating coils for inductively heating to-be-heated object are provided under a top plate on which to-be-heated object is placed, and plural inverter circuits for supplying high-frequency currents to the plural induction heating coils, respectively, are adapted to be cooled by cooling air flows from cooling portions, and placed in a longitudinal row along the cooling air flows, in air-flow blowing path spaces through which cooling air flows from the cooling portions are blown, so as to facilitate cooling designing for an induction heating device and to improve the cooling performance of the induction heating device.