Abstract: An improved structure of an image sensor includes a substrate, a frame layer on the substrate to form a chamber together with the substrate, a photosensitive chip arranged on the substrate and within the chamber, a plurality of wires, a transparent layer placed on the frame layer, and a filling medium. The frame layer is formed with at least one venthole communicating with the chamber. The wires electrically connect the chip to the substrate. The filling medium is filled into the venthole of the frame layer to seal the chamber. Accordingly, the air pressure within the chamber generated when the transparent layer is fixed to the frame layer may be released through the venthole, and the transparent layer may be firmly fixed to the frame layer.