A complementary metal-oxide silicon (CMOS) image sensor includes a semiconductor layer of a first conductivity type, a plurality of pixels located in the semiconductor layer, a photoelectric converter located in each of the plurality of pixels in the semiconductor layer and includes a region doped with impurities of a second conductivity type. The CMOS image sensor further includes a deep well of a first conductivity type located in a lower position than the photoelectric converter in the semiconductor layer and has a higher impurity concentration than that of the semiconductor layer. The deep well is located only in a portion of each of the plurality of pixels.