Abstract: A smell sensor includes an ion sensor in which a sensing section provided with a sensitive film configured to change a potential in accordance with a state of a measurement target is formed on a semiconductor substrate; a substance adsorption film disposed on the sensitive film and configured to change the state with adsorption of a smell substance; and a reference electrode configured to apply a reference voltage to the substance adsorption film. The reference electrode is disposed to be separated from the sensitive film and not to overlap the sensing section when viewed in a thickness direction of the semiconductor substrate.

Abstract: The ion sensor includes a substrate and a plurality of detection units. Each detection unit includes an ID portion, an ICG electrode, a TG electrode, an SG electrode, an electrode pad, and an ion sensitive film. The SG electrode is disposed between the ICG electrode and the TG electrode on the main surface of the substrate. The electrode pad is electrically connected to the SG electrode and disposed on the opposite side of the SG electrode from the substrate. The ion sensitive film is provided on the surface of the electrode pad, and changes a potential according to change in ion concentration of the aqueous solution in contact with the ion sensitive film. A width of the ion sensitive film in a facing direction in which the ICG electrode and the TG electrode face each other is greater than a separation width between the ICG electrode and the TG electrode.

Abstract: A smell sensor includes an ion sensor in which a sensing section provided with a sensitive film configured to change a potential in accordance with a state of a measurement target is formed on a semiconductor substrate; a substance adsorption film disposed on the sensitive film and configured to change the state with adsorption of a smell substance; and a reference electrode configured to apply a reference voltage to the substance adsorption film. The reference electrode is disposed to be separated from the sensitive film and not to overlap the sensing section when viewed in a thickness direction of the semiconductor substrate.