A high-frequency heating device (200, 300, 500, 600) comprising: a first surface wave excitation body (203a, 303a, 503a, 603a) and a second surface wave excitation body (203b, 303b, 503b, 603b) configured to propagate the high-frequency power as respective surface waves to heat a heating-target object; a high-frequency power supply unit (210, 310a); a high-frequency power generation unit (220, 320) configured to generate high-frequency power and to supply the high-frequency power only to the first surface wave excitation body (203a, 303a, 503a, 603a), wherein the high-frequency power is supplied to the first surface wave excitation body via the high-frequency power supply unit (210, 310a); and a stand on which the heating-target object is mounted, wherein the first and second surface wave excitation bodies (203a, 303a, 503a, 603a, 203b, 303b, 503b, 603b) are disposed at locations opposite to each other in such a manner that the heating-target object is put between them and characterized in that spatial coupling is obtained between the first and second surface wave excitation bodies (203a, 303a, 503a, 603a, 203b, 303b, 503b, 603b), such that a part of high-frequency power propagating as a surface wave along the first surface wave excitation body (203a, 303a, 503a, 603a) is supplied by spatial coupling to the second surface wave excitation body (203b, 303b, 503b, 603b), and such that the heating-target object is heated by the high-frequency power propagating as the surface wave along the first surface wave excitation body (203a, 303a, 503a, 603a) and the second surface wave excitation body (203b, 303b, 503b, 603b). a first surface wave excitation body (203a, 303a, 503a, 603a) and a second surface wave excitation body (203b, 303b, 503b, 603b) configured to propagate the high-frequency power as respective surface waves to heat a heating-target object; a high-frequency power supply unit (210, 310a); a high-frequency power generation unit (220, 320) configured to generate high-frequency power and to supply the high-frequency power only to the first surface wave excitation body (203a, 303a, 503a, 603a), wherein the high-frequency power is supplied to the first surface wave excitation body via the high-frequency power supply unit (210, 310a); and a stand on which the heating-target object is mounted, wherein the first and second surface wave excitation bodies (203a, 303a, 503a, 603a, 203b, 303b, 503b, 603b) are disposed at locations opposite to each other in such a manner that the heating-target object is put between them and characterized in that spatial coupling is obtained between the first and second surface wave excitation bodies (203a, 303a, 503a, 603a, 203b, 303b, 503b, 603b), such that a part of high-frequency power propagating as a surface wave along the first surface wave excitation body (203a, 303a, 503a, 603a) is supplied by spatial coupling to the second surface wave excitation body (203b, 303b, 503b, 603b), and such that the heating-target object is heated by the high-frequency power propagating as the surface wave along the first surface wave excitation body (203a, 303a, 503a, 603a) and the second surface wave excitation body (203b, 303b, 503b, 603b).