An ignition or plasma generation apparatus for using a combination of an electrical discharge and energy derived from electromagnetic waves to initiate a combustion reaction, a chemical reaction, or a plasma reaction in a reaction region, the ignition or plasma generation apparatus comprising: a plug (100;120;130;140;150) and a mixing means (60;70), wherein said mixing means (60;70) includes: a first input section (21;61), a second input section (25;62), an output section (28;63) connected to said second input section (25;62), a dielectric substrate and a capacitor; said first input section (21;61) for receiving an input of said energy derived from said electromagnetic waves generated by an electromagnetic wave generator and said second input section (25;62) for receiving an energy for said electrical discharge, wherein said second input section (25;62) and said output section (28;63) are disposed on one surface of said dielectric substrate, and said first input section (21;61) is disposed on the other surface of said dielectric substrate, wherein said first input section (31;21) is electrically coupled to said output section (28;63) by an electric field coupling wherein said capacitor comprises a conductive pattern (64A,64B) disposed in an opposite manner on respective said surfaces of said dielectric substrate so as to define a capacitance configured to generate said electric field coupling; wherein said mixing means (60;70) is configured - to mix said energy for said electrical discharge and said energy from said electromagnetic waves; - to supply an output of said mixed energies, superimposed on each other on a same transmission line, to said plug (100;120;130;140;150); and wherein said plug (100;120;130;140;150) is configured to introduce said mixed energies to said reaction region. a plug (100;120;130;140;150) and a mixing means (60;70), a first input section (21;61), a second input section (25;62), an output section (28;63) connected to said second input section (25;62), a dielectric substrate and a capacitor; said first input section (21;61) for receiving an input of said energy derived from said electromagnetic waves generated by an electromagnetic wave generator and said second input section (25;62) for receiving an energy for said electrical discharge, wherein said second input section (25;62) and said output section (28;63) are disposed on one surface of said dielectric substrate, and said first input section (21;61) is disposed on the other surface of said dielectric substrate, wherein said first input section (31;21) is electrically coupled to said output section (28;63) by an electric field coupling wherein said capacitor comprises a conductive pattern (64A,64B) disposed in an opposite manner on respective said surfaces of said dielectric substrate so as to define a capacitance configured to generate said electric field coupling; wherein said mixing means (60;70) is configured - to mix said energy for said electrical discharge and said energy from said electromagnetic waves; - to supply an output of said mixed energies, superimposed on each other on a same transmission line, to said plug (100;120;130;140;150); - to mix said energy for said electrical discharge and said energy from said electromagnetic waves; - to supply an output of said mixed energies, superimposed on each other on a same transmission line, to said plug (100;120;130;140;150); and wherein said plug (100;120;130;140;150) is configured to introduce said mixed energies to said reaction region.