An image sensor and a method for manufacturing the sensor are provided for reducing loss of light reflected from photodiodes, and thus, improving light efficiency. The method of manufacturing an image sensor can include providing a semiconductor substrate having a photodiode; and then forming a reflective film frame on the photodiode, the reflective film frame having sidewalls that are inclined with respect to the uppermost surface of the photodiode; and then forming an opening over the surface of the reflective film frame and corresponding to the photodiode by forming a reflective film on the sidewalls of the reflective film frame.