A structure for a liquid treatment device (100, 200, 300, 400, 500) for the treatment of a first liquid to be treated, the first liquid to be treated containing a component that can be oxidatively decomposed by an oxidation reaction by utilizing anaerobic microorganisms, the structure having a first surface and a second surface, each one of the first surface and the second surface defining an outer surface of the structure, the inside of the structure being between the first surface and the second surface, the structure comprising: an ion transfer layer arranged inside the structure between the first surface and the second surface, the ion transfer layer allowing hydrogen ions to move therethrough; and a conductor arranged inside the structure between the first surface and the second surface, the conductor including a first portion exposed to the outside of the structure at the first surface and a second portion exposed to the outside of the structure at the second surface, at least a part of the conductor being located inside the ion transfer layer, and the conductor electrically connecting the first portion, which is suitable to function as an anode, and the second portion (11 b), which is suitable to function as a cathode; wherein: the first portion of the conductor is suitable to be arranged so as to be in contact with the first liquid to be treated; the second portion (11 b) of the conductor is suitable to be arranged so as to be in contact with a gas containing oxygen or a second liquid to be treated; the structure is adapted to allow hydrogen ions to move inside the structure through the ion transfer layer from the side of the first surface to the side of the second surface; the structure is adapted to allow electrons to move inside the structure through the conductor from the side of the first surface to the side of the second surface; and the structure is arranged so as to suppress movement of the first liquid to be treated to the side of the gas containing oxygen or of the second liquid to be treated and to suppress movement of the gas containing oxygen or the second liquid to be treated to the side of the first liquid to be treated. an ion transfer layer arranged inside the structure between the first surface and the second surface, the ion transfer layer allowing hydrogen ions to move therethrough; and a conductor arranged inside the structure between the first surface and the second surface, the conductor including a first portion exposed to the outside of the structure at the first surface and a second portion exposed to the outside of the structure at the second surface, at least a part of the conductor being located inside the ion transfer layer, and the conductor electrically connecting the first portion, which is suitable to function as an anode, and the second portion (11 b), which is suitable to function as a cathode; wherein: the first portion of the conductor is suitable to be arranged so as to be in contact with the first liquid to be treated; the second portion (11 b) of the conductor is suitable to be arranged so as to be in contact with a gas containing oxygen or a second liquid to be treated; the structure is adapted to allow hydrogen ions to move inside the structure through the ion transfer layer from the side of the first surface to the side of the second surface; the structure is adapted to allow electrons to move inside the structure through the conductor from the side of the first surface to the side of the second surface; and the structure is arranged so as to suppress movement of the first liquid to be treated to the side of the gas containing oxygen or of the second liquid to be treated and to suppress movement of the gas containing oxygen or the second liquid to be treated to the side of the first liquid to be treated. the first portion of the conductor is suitable to be arranged so as to be in contact with the first liquid to be treated; the second portion (11 b) of the conductor is suitable to be arranged so as to be in contact with a gas containing oxygen or a second liquid to be treated; the structure is adapted to allow hydrogen ions to move inside the structure through the ion transfer layer from the side of the first surface to the side of the second surface; the structure is adapted to allow electrons to move inside the structure through the conductor from the side of the first surface to the side of the second surface; and the structure is arranged so as to suppress movement of the first liquid to be treated to the side of the gas containing oxygen or of the second liquid to be treated and to suppress movement of the gas containing oxygen or the second liquid to be treated to the side of the first liquid to be treated.