An active gas generation apparatus arranged to generate an active gas obtained by activating a raw material gas supplied to a discharge space , the active gas generation apparatus comprising: a high frequency power supply ; a first electrode component ; and a second electrode component provided below said first electrode component, wherein said first electrode component has a first electrode dielectric film and a first metal electrode formed on an upper surface of said first electrode dielectric film, wherein said second electrode component has a second electrode dielectric film and a second metal electrode formed on a lower surface of said second electrode dielectric film, wherein the high frequency power supply is arranged to apply an AC voltage between said first and second metal electrodes, wherein a dielectric space in which said first and second electrode dielectric films face each other includes, as said discharge space, an area where said first and second metal electrodes overlap each other in plan view, wherein said second electrode dielectric film has a gas ejection hole for ejecting said active gas outside, and a path from said discharge space to said gas ejection hole is defined as an active gas flow path, said first electrode component further has an auxiliary conductive film formed, independently of said first metal electrode, on the upper surface of said first electrode dielectric film, said auxiliary conductive film is provided to overlap part of said active gas flow path in plan view, and said auxiliary conductive film is set to a ground potential, and said active gas generation apparatus further comprises an active gas auxiliary member provided to fill part of said active gas flow path between said discharge space and said gas ejection hole in said dielectric space. activating a raw material gas supplied to a discharge space , the active gas generation apparatus comprising: a high frequency power supply ; a first electrode component ; and a second electrode component provided below said first electrode component, wherein said first electrode component has a first electrode dielectric film and a first metal electrode formed on an upper surface of said first electrode dielectric film, wherein said second electrode component has a second electrode dielectric film and a second metal electrode formed on a lower surface of said second electrode dielectric film, wherein the high frequency power supply is arranged to apply an AC voltage between said first and second metal electrodes, wherein a dielectric space in which said first and second electrode dielectric films face each other includes, as said discharge space, an area where said first and second metal electrodes overlap each other in plan view, wherein said second electrode dielectric film has a gas ejection hole for ejecting said active gas outside, and a path from said discharge space to said gas ejection hole is defined as an active gas flow path, said first electrode component further has an auxiliary conductive film formed, independently of said first metal electrode, on the upper surface of said first electrode dielectric film, said auxiliary conductive film is provided to overlap part of said active gas flow path in plan view, and said auxiliary conductive film is set to a ground potential, and said active gas generation apparatus further comprises an active gas auxiliary member provided to fill part of said active gas flow path between said discharge space and said gas ejection hole in said dielectric space. <EOS>