A back surface irradiated photoelectric conversion apparatus, comprising: a semiconductor layer having a front surface and a back surface and in which a plurality of photoelectric conversion portions is provided between the front surface and the back surface; a wiring structure arranged on the front surface side of the semiconductor layer; a separation portion arranged between the plurality of photoelectric conversion portions and formed by a trench continuing from the back surface; a first light shielding portion arranged above the semiconductor layer on the back surface side so as to overlap the separation portion; and a second light shielding portion arranged above the semiconductor layer on the back surface side so as to face the first light shielding portion via a region arranged above at least one photoelectric conversion portion among the plurality of photoelectric conversion portions, wherein a surface of the first light shielding portion that is located so as to face the second light shielding portion has a first edge located on the semiconductor layer side, wherein a surface of the second light shielding portion that is arranged so as to face the first light shielding portion has a second edge located on an opposite side of the second light shielding portion to the semiconductor layer side, and a boundary between the back surface and a side surface of the separation portion that is arranged adjacent the photoelectric conversion portion side is positioned below the first light shielding portion, and characterised in that H/D > (W + L)/L is satisfied, where W is the distance between the first edge and the second edge in a first direction along the back surface of the semiconductor layer, L is the distance between the first edge and the boundary in the first direction, H is the distance between the back surface and the second edge in a second direction from the front surface toward the back surface of the semiconductor layer, and D is the distance between the first edge and the boundary in the second direction. a semiconductor layer having a front surface and a back surface and in which a plurality of photoelectric conversion portions is provided between the front surface and the back surface; a wiring structure arranged on the front surface side of the semiconductor layer; a separation portion arranged between the plurality of photoelectric conversion portions and formed by a trench continuing from the back surface; a first light shielding portion arranged above the semiconductor layer on the back surface side so as to overlap the separation portion; and a second light shielding portion arranged above the semiconductor layer on the back surface side so as to face the first light shielding portion via a region arranged above at least one photoelectric conversion portion among the plurality of photoelectric conversion portions, wherein a surface of the first light shielding portion that is located so as to face the second light shielding portion has a first edge located on the semiconductor layer side, wherein a surface of the second light shielding portion that is arranged so as to face the first light shielding portion has a second edge located on an opposite side of the second light shielding portion to the semiconductor layer side, and a boundary between the back surface and a side surface of the separation portion that is arranged adjacent the photoelectric conversion portion side is positioned below the first light shielding portion, and characterised in that H/D > (W + L)/L is satisfied, where W is the distance between the first edge and the second edge in a first direction along the back surface of the semiconductor layer, L is the distance between the first edge and the boundary in the first direction, H is the distance between the back surface and the second edge in a second direction from the front surface toward the back surface of the semiconductor layer, and D is the distance between the first edge and the boundary in the second direction.