In a photoelectric conversion element which is formed by alternately stacking a region of a first conductivity type and a region of a second conductivity type as a conductivity type opposite to the first conductivity type to form a multi-layered structure, in which junction surfaces between the neighboring regions of the first and second conductivity types are formed to have depths suited to photoelectrically convert light in a plurality of different wavelength ranges, and which outputs signals for respective wavelength ranges, a region of a conductivity type opposite to the conductivity type of a surface-side region of the junction surface closest to a surface is formed in the surface of the surface-side region. Thus, highly color-separable signals which suffer less color mixture upon reading out signals from a plurality of photodiode layers is read out.