Disclosed are an image sensor including a light collection member having a multi-layer step shape and an electronic device including the same. This technology can improve light condensing efficiency in a unit pixel since a corresponding pixel lens is included. Furthermore, light condensing efficiency in a unit pixel can be improved more effectively by controlling the width of a corresponding pixel lens so that the pixel lens corresponds to the wavelength of incident light whose color has been separated by a corresponding color filter. As described above, quantum efficiency in the photoelectric conversion element can also be improved since light condensing efficiency in a unit pixel is improved. As a result, performance of the image sensor can be improved.