A photoelectric conversion element comprising: a photoelectric conversion layer; and a plurality of metal nanoparticles arranged in the form of a two-dimensional array on the photoelectric conversion layer on its principal face side that is opposite to its light receiving face, wherein the plurality of metal nanoparticles are arranged with a particle density that is equal to or greater than 5.0×108/cm2 and is equal to or smaller than 3.0×109/cm2.