A back side illumination image sensor reduced in chip size has a capacitor disposed in a vertical upper portion of a pixel region in the back side illumination image sensor in which light is illuminated from a back side of a subscriber, thereby reducing a chip size, and a method for manufacturing the back side illumination image sensor. The capacitor of the back side illumination image sensor reduced in chip size is formed in the vertical upper portion of the pixel region, not in the outside of a pixel region, so that the outside area of the pixel region for forming the capacitor is not required, thereby reducing a chip size.