An analysis apparatus includes an electric field enhancing element including a metallic layer, a light-transmissive layer, and a plurality of metallic particles arranged in a first direction and a second direction intersecting with the first direction a light source irradiating the electric field enhancing element with at least one of linearly polarized light polarized in the first direction, linearly polarized light polarized in the second direction, and circularly polarized light and a detector, in which localized surface plasmon and propagating surface plasmon are electromagnetically interacted, and when a thickness of the light-transmissive layer is G [nm], an effective reflective index of the light-transmissive layer is neff, and a wavelength of the excitation light is λi [nm], a relationship of the following expression (1) is satisfied.20 [nm]
