A light-receiving element, wherein the light-receiving element is a current assisted photonic demodulator (CAPD) sensor in a back-illuminated type, the light-receiving element comprising a pixel array unit, wherein the pixel array unit comprises a discharge region and an effective pixel region, wherein the discharge region is provided on an outer side of the effective pixel region to suppress electron accumulation in a region other than the effective pixel region and wherein the effective pixel region comprises a pixel comprising: an on-chip lens; an interconnection layer comprising an interconnection for driving a transistor in the pixel or reading out a signal from the pixel; and a semiconductor layer that is disposed between the on-chip lens and the interconnection layer, wherein the semiconductor layer includes: a first voltage application unit to which a first voltage is applied, a second voltage application unit to which a second voltage different from the first voltage is applied, a first charge detection unit that is disposed to surround the periphery of the first voltage application unit and detects the amount of signal carriers generated due to photoelectric conversion by the semiconductor layer, a second charge detection unit that is disposed to surround the periphery of the second voltage application unit and detects the amount of signal carriers generated due to photoelectric conversion by the semiconductor layer. and wherein the effective pixel region comprises a pixel comprising: an on-chip lens; an interconnection layer comprising an interconnection for driving a transistor in the pixel or reading out a signal from the pixel; and an on-chip lens; an interconnection layer comprising an interconnection for driving a transistor in the pixel or reading out a signal from the pixel; and a semiconductor layer that is disposed between the on-chip lens and the interconnection layer, wherein the semiconductor layer includes: a first voltage application unit to which a first voltage is applied, a second voltage application unit to which a second voltage different from the first voltage is applied, a first charge detection unit that is disposed to surround the periphery of the first voltage application unit and detects the amount of signal carriers generated due to photoelectric conversion by the semiconductor layer, a second charge detection unit that is disposed to surround the periphery of the second voltage application unit and detects the amount of signal carriers generated due to photoelectric conversion by the semiconductor layer. a first voltage application unit to which a first voltage is applied, a second voltage application unit to which a second voltage different from the first voltage is applied, a first charge detection unit that is disposed to surround the periphery of the first voltage application unit and detects the amount of signal carriers generated due to photoelectric conversion by the semiconductor layer, a second charge detection unit that is disposed to surround the periphery of the second voltage application unit and detects the amount of signal carriers generated due to photoelectric conversion by the semiconductor layer.