Disclosed are a scintillator using semiconductor quantum dots, a method of manufacturing the scintillator, and a digital image diagnostic system employing the scintillator. In one aspect, the scintillator includes a metallic reflection film made of a metal configured to transmit an X-ray and reflecting visible light and having a plurality of voids formed in a thickness direction. The scintillator also includes a polymer film formed inside the plurality of voids and being configured to include a plurality of columnar structures to convert the X-ray into the visible light. The scintillator further includes semiconductor quantum dots dispersed in the polymer film and having a decay time of tens of nanoseconds.
