The disclosure provides a scanning device including a flatbed scanner and an ADF. The flatbed scanner includes a first body, a transparent substrate disposed on top surface of the first body, a first film disposed on top surface of the transparent substrate, and an image capturing module disposed under bottom surface of the transparent substrate. The ADF includes a second body, a backplane disposed at bottom of the second body for covering top surface of the flatbed scanner, a paper passage disposed inside the ADF, and a second film. An open portion is configured in the paper passage corresponding to top surface of the transparent substrate, and results communication between the paper passage and top surface of the transparent substrate. The second film is disposed at paper entrance of the open portion. Wherein, the first film and the second film are not overlap on top surface of the transparent substrate.