An image sensor having active, peripheral and dummy regions is provided as follows. A dummy through electrode is disposed in the substrate. An active through electrode is disposed in the substrate. An insulation structure in which a color filter is embedded is disposed on the substrate. A dummy bottom electrode is disposed on the insulation structure and connected electrically to the dummy through electrode. An active bottom electrode is disposed on the insulation structure and connected electrically to the active through electrode. A photoelectric conversion layer is disposed on the insulation structure. A top electrode is disposed on the photoelectric conversion layer and the dummy bottom electrode. The top electrode is connected electrically to the dummy bottom electrode. The photoelectric conversion layer is interposed between the top electrode and the active bottom electrode which are separated from each other.