There are provided a photoelectric conversion element and a photoelectric conversion element module including the photoelectric conversion element, the photoelectric conversion element including a transparent substrate, a transparent conductive layer arranged on the transparent substrate, a photoelectric conversion layer arranged on the transparent conductive layer, a porous insulating layer arranged in contact with the photoelectric conversion layer, a reflective layer arranged in contact with the porous insulating layer, and a catalyst layer and a counter conductive layer that are arranged on the reflective layer, in which the photoelectric conversion layer contains a porous semiconductor, a carrier-transport material, and a photosensitizer, and in which the area of the orthogonal projection of the porous insulating layer onto the transparent substrate and the area of the orthogonal projection of the reflective layer onto the transparent substrate are each larger than the area of the orthogonal projection of the photoelectric conversion layer onto the transparent substrate.