A control unit of an induction heating unit controls AC power output to a heating coil of a transverse type induction heating unit that allows an alternating magnetic field to intersect a sheet surface of a conductive sheet that is being conveyed to inductively heat the conductive sheet. The control unit includes: a magnetic energy recovery switch that outputs AC power to the heating coil; a frequency setting unit that sets an output frequency in response to at least one of the relative permeability, resistivity, and sheet thickness of the conductive sheet; and a gate control unit that controls a switching operation of the magnetic energy recovery switch on the basis of the output frequency set by the frequency setting unit.