An induction heating system which allows an alternating magnetic field to intersect a sheet surface of a conductive sheet which is being conveyed to inductively heat the conductive sheet, the induction heating system comprising: a transverse type induction heating unit including a heating coil (24, 28) which is disposed to face the sheet surface of the conductive sheet; and a control unit (100, 200) which controls an AC power to output to the heating coil (24,28), wherein the induction heating unit includes: a core (23, 27) around which the heating coil (24, 28) is wound; and a shielding plate (31a, 31b, 31c, 31d, 301a, 301b, 301c, 301d) which is disposed to face a region including an edge of the conductive sheet in a width direction, and the control unit (100, 200) includes: a magnetic energy recovery switch which outputs the AC power to the heating coil (24,28); a frequency setting unit which sets an output frequency in response to at least one of a relative permeability, a resistivity, and a sheet thickness of the conductive sheet; and a gate control unit which controls a switching operation of the magnetic energy recovery switch on the basis of the output frequency set by the frequency setting unit, and characterised in that has a depressed portion (51,52) the shielding plate (301a, 301b, 301c, 301d) has a depressed portion (51,52) at a surface which faces the conductive sheet, is configured to be disposed in such a manner that the depressed portion (51, 52) of the shielding plate (31a, 31b, 31c, 31d, 301a, 301b, 301c, 30d) and a sheet surface of the conductive sheet are opposite to each other in the vicinity of an edge of the conductive sheet in the sheet width direction, and is formed from a conductor having a relative permeability of 1. a transverse type induction heating unit including a heating coil (24, 28) which is disposed to face the sheet surface of the conductive sheet; and a control unit (100, 200) which controls an AC power to output to the heating coil (24,28), wherein the induction heating unit includes: a core (23, 27) around which the heating coil (24, 28) is wound; and a shielding plate (31a, 31b, 31c, 31d, 301a, 301b, 301c, 301d) which is disposed to face a region including an edge of the conductive sheet in a width direction, and the control unit (100, 200) includes: a magnetic energy recovery switch which outputs the AC power to the heating coil (24,28); a frequency setting unit which sets an output frequency in response to at least one of a relative permeability, a resistivity, and a sheet thickness of the conductive sheet; and a gate control unit which controls a switching operation of the magnetic energy recovery switch on the basis of the output frequency set by the frequency setting unit, and characterised in that has a depressed portion (51,52) the shielding plate (301a, 301b, 301c, 301d) has a depressed portion (51,52) at a surface which faces the conductive sheet, is configured to be disposed in such a manner that the depressed portion (51, 52) of the shielding plate (31a, 31b, 31c, 31d, 301a, 301b, 301c, 30d) and a sheet surface of the conductive sheet are opposite to each other in the vicinity of an edge of the conductive sheet in the sheet width direction, and is formed from a conductor having a relative permeability of 1. a core (23, 27) around which the heating coil (24, 28) is wound; and a shielding plate (31a, 31b, 31c, 31d, 301a, 301b, 301c, 301d) which is disposed to face a region including an edge of the conductive sheet in a width direction, and the control unit (100, 200) includes: a magnetic energy recovery switch which outputs the AC power to the heating coil (24,28); a frequency setting unit which sets an output frequency in response to at least one of a relative permeability, a resistivity, and a sheet thickness of the conductive sheet; and a gate control unit which controls a switching operation of the magnetic energy recovery switch on the basis of the output frequency set by the frequency setting unit, and characterised in that has a depressed portion (51,52) the shielding plate (301a, 301b, 301c, 301d) has a depressed portion (51,52) at a surface which faces the conductive sheet, is configured to be disposed in such a manner that the depressed portion (51, 52) of the shielding plate (31a, 31b, 31c, 31d, 301a, 301b, 301c, 30d) and a sheet surface of the conductive sheet are opposite to each other in the vicinity of an edge of the conductive sheet in the sheet width direction, and is formed from a conductor having a relative permeability of 1. a magnetic energy recovery switch which outputs the AC power to the heating coil (24,28); a frequency setting unit which sets an output frequency in response to at least one of a relative permeability, a resistivity, and a sheet thickness of the conductive sheet; and a gate control unit which controls a switching operation of the magnetic energy recovery switch on the basis of the output frequency set by the frequency setting unit, and characterised in that has a depressed portion (51,52) the shielding plate (301a, 301b, 301c, 301d) has a depressed portion (51,52) at a surface which faces the conductive sheet, is configured to be disposed in such a manner that the depressed portion (51, 52) of the shielding plate (31a, 31b, 31c, 31d, 301a, 301b, 301c, 30d) and a sheet surface of the conductive sheet are opposite to each other in the vicinity of an edge of the conductive sheet in the sheet width direction, and is formed from a conductor having a relative permeability of 1.