Disclosed is a photoelectric conversion element including a cell. The cell includes an electrode substrate, a counter substrate, an oxide semiconductor layer provided on the electrode substrate, an electrolyte provided between the electrode substrate and the counter substrate, and an annular sealing portion joining the electrode substrate and the counter substrate. The layer includes a main body portion provided inside the sealing portion and on the electrode substrate and extending straight from the electrode substrate toward the counter substrate, and a protruding portion which protrudes from the main body portion toward the sealing portion and does not come into contact with the electrode substrate. A width of a second surface of the layer facing the counter substrate is longer than a width of a first surface which is a boundary surface between the layer and the electrode substrate in a cross section along a thickness direction of the layer.