A photoelectric conversion device including a plurality of substrates in a stacked state, the plurality of substrates including a first substrate and a second substrate electrically connected to each other, the photoelectric conversion device comprising: a memory cell unit including row-selection lines that are to be driven upon selection of a row of a memory cell array and column-selection lines that are to be driven upon selection of a column of the memory cell array; and a memory peripheral circuit unit that includes row-selection line connection portions and column-selection line connection portions so as to drive the row-selection lines and to drive the column-selection lines, wherein a first portion that is at least a part of the memory peripheral circuit unit is formed on the first substrate and the memory cell unit is formed on the second substrate.