A method for manufacturing a photoelectric conversion element includes providing a base structure including a semiconductor substrate having a principal surface, a first electrode located on or above the principal surface, second electrodes which are located on or above the principal surface and which are one- or two-dimensionally arranged, and a photoelectric conversion film covering at least the second electrodes; forming a mask layer on the photoelectric conversion film, the mask layer being conductive and including a covering section covering a portion of the photoelectric conversion film that overlaps the second electrodes in plan view; and partially removing the photoelectric conversion film by immersing the base structure and the mask layer in an etchant.