Disclosed are an image sensor and a method for manufacturing the same. The image sensor includes an isolation trench formed in a semiconductor substrate corresponding to a logic region and a pixel separating trench formed on the semiconductor substrate corresponding to a pixel region and having a depth shallower than a depth of the isolation trench of the logic region, a barrier region formed below the pixel separating trench, a pixel separator formed inside the pixel separating trench, a gate formed above the semiconductor substrate, a first doped region formed at a deep region of the semiconductor substrate corresponding to one side of the gate, an additionally-doped region interposed between the first doped region and the barrier region, and a second doped region formed at a shallow region of the semiconductor substrate such that the second doped region makes contact with the first doped region.