A vertically integrated sensor based on standard CMOS process, which can detect the wavelength of the monochromatic spectrum, was designed, manufactured and tested. It took the advantage of the two-layer structure of the device which can sense short wavelength and long wavelength illumination (among near UV, visible and near IR) simultaneously,then through these two different responses, the final device response showed monotonically increasing with the wavelength, and the wavelength can be known through this monotonicity. First we introduced the basic principle of the device, then the ideas in test device design were given. Finally, the authors measured the manufactured device, and the QEs of the device and the monotonic relationship between the device and the wavelength of the monochromatic spectrum were given.