A detection device and a method of manufacturing the same are disclosed. The detection device includes a detection module and a housing module disposed on the detection module. The detection module includes a substrate, an emission unit, and a detection unit. The substrate includes an emission end area on which the emission unit is disposed, and a receiver end area on which the detection unit is disposed. The housing module includes a plastic housing unit having a receiving space and an opening, and a metallic shielding unit disposed on the plastic housing unit. The receiving space is divided into a first receiving space and a second receiving space by the metallic shielding unit, and the opening is divided into an emission hole and a detection hole by the metallic shielding unit. By the above-mentioned means, the distance between the emission hole and the detection hole is reduced.