Provided is an image sensor including a semiconductor substrate having a trench and having a first conductivity type, a photoelectric conversion layer formed in the semiconductor substrate below the trench to have a second conductivity type, first and second transfer gate electrodes provided in the trench covered with a gate insulating layer, a first charge-detection layer formed in the semiconductor substrate adjacent to the first transfer gate electrode, and a second charge-detection layer formed in the semiconductor substrate adjacent to the second transfer gate electrode.