Provided is an image sensor comprising a color separation element. The image sensor includes a pixel array including a plurality of a first pixels, a plurality of second pixels, and a plurality of third pixels; color separation elements configured to direct light in a second wavelength band travel toward the second pixels and direct a mixture light in a first wavelength band and light in a third wavelength band travel toward the first pixels or the third pixels; and a color filter layer including a first color filter, a second color filter, and a third color filter, wherein the pass bandwidth of the second color filter is greater than the pass bandwidth of each of the first and third color filters.