To provide a media authenticity determination device, capable of excluding a high-grade forged coin which is within the standard values of authenticity determination criterion and can be determined conventionally as an authentic medium and improving the reliability for accurate authenticity determination, without deteriorating its processing efficiency.

When there exist a specific amount or more of the kinds of media in the vicinity of a standard value or in a fixed range, even if the media supplied are within the standard values for authenticity determination, the media authenticity determination device makes a guess that they have a high possibility of being high-grade forged coins prepared via specific manufacturing processes, and returns the media kinds regarded as forged coins.