A coin discrimination system eliminates the task of visiting the location of an existing coin depositing/dispensing machine to exchange an existing coin discrimination apparatus incorporated in the machine for a new one and the task of additionally setting a new coin discrimination criterion manually to the existing apparatus. Pieces of specific information from pieces of sensor information are compared with pieces of current discrimination criterion information, conducting authenticity and denomination discrimination of coins. New discrimination criterion information setting coins are selected through judgement on whether the denomination of each coin is consistent with a target denomination and judgement on whether each coin is suitable for generating new discrimination criterion information while conducting the authentication and denomination discrimination. A piece of new specific information is extracted from the pieces of sensor information about the setting coins. The piece of new discrimination criterion information is set using the piece of new specific information.