A CMOS image sensor and a method for manufacturing the same improve light-receiving efficiency and maintain a margin in the design of a metal line. The CMOS image sensor includes a transparent substrate including an active area having a photodiode region and a transistor region and a field area for isolation of the active area, a p-type semiconductor layer on the transparent substrate, a photodiode in the p-type semiconductor layer corresponding to the photodiode region, and a plurality of transistors in the p-type semiconductor layer corresponding to the transistor region.