An image sensor includes: a sensor substrate including a plurality of first pixels and a plurality of second pixels; a spacer layer on the sensor substrate; and a color separating lens array on the spacer layer and changing condensing light of a first wavelength on each of the first pixels and condensing light of a second wavelength on each of the second pixels. The color separating lens array includes a first color separating lens array layer including a plurality of first nanoposts, a first dielectric material layer arranged among the plurality of first nanoposts, and a plurality of first etch prevention patterns arranged respectively under the plurality of first nanoposts.