We report an ultrathin digital camera having a monolithic light blocking structure for high-contrast NIR imaging. This ultrathin camera features inverted microlens arrays (MLAs), light blocking layers composed of metal and black photoresist, spacers and an image sensor. The imaging results through the camera with the light blocking structure showed that the MTF 50 was enhanced about twice and the Michelson contrast increased about 4 times than the value without the layers. Imaging for counterfeit bill discrimination was successfully performed using the ultrathin digital camera. This ultrathin camera can offer a new opportunity in the field of surveillance, and biomedical imaging.