Disclosed is an image sensor including a substrate having a first surface and a second surface opposite to each other, a first photoelectric conversion region and a second photoelectric conversion region in the substrate, a through electrode between the first and second photoelectric conversion regions, an insulation structure on the second surface of the substrate, a first color filter and a second color filter respectively provided on the first and second photoelectric conversion regions, and a photoelectric conversion layer on the insulation structure and electrically connected to the through electrode. The through electrode include a first end adjacent to the first surface and a second end adjacent to the second surface. The first end has a non-planar shape.