An image sensor includes an insulating pattern disposed on a semiconductor substrate and having an opening, a color filter disposed within the opening of the insulating pattern, a capping insulating layer disposed on the color filter, a first electrode disposed on the capping insulating layer and having a portion overlapping with the color filter, a separation structure surrounding a side surface of the first electrode, and a photoelectric layer disposed on the first electrode. The separation structure includes a first insulating layer and a second insulating layer formed of different material.