A commodity management system can manage information on commodities and commodity owners from sale times to disposal times and can identify a new owner in a disposal/recycling procedure. In an IC tag embedded in a motorcycle, management information associating the motorcycle and its owner is stored. A management card for recording the same management information is issued to a purchaser of the motorcycle. When the motorcycle is disposed and recycled, the dealer transmits a request for authentication of the owner to a management server. The management server then allows a disposal/recording procedure only if the management information stored in the IC tag embedded in the motorcycle matches the management information recorded in the management card.