A photochemical electrode includes: an electrically conductive layer; and a photoexcitation material layer provided over the electrically conductive layer and including a photoexcitation material, wherein the photoexcitation material layer is one of a first photoexcitation material layer in which a potential of the conduction band minimum decreases from a second surface opposite to a first surface on the side of the electrically conductive layer toward the first surface and a second photoexcitation material layer in which a potential of the valence band maximum decreases from the second surface toward the first surface.