Provided is an image sensor including a light sensor array including a plurality of light sensors configured to detect an incident light and convert the incident light into an electrical signal, the plurality of light sensors being are provided in a plurality of pixels, a transparent layer provided on the light sensor array, a color separation element provided on the transparent layer and configured to separate the incident light into light of a plurality of colors based on a wavelength band, and a focusing element including a nanostructure in a region corresponding to at least one pixel among the plurality of pixels and configured to perform auto focusing.