A signature device having an item selection input section which accepts a selection of a group of items formed by combining an item delivered from at least one supplier and an item generated by itself, a path verification information updating section which updates path verification information to verify a delivery route included in the signature information on the delivered item, a signature information preparation section which prepares new signature information from a signature prepared by itself and the updated path verification information with respect to the selected item group, and a signature information transmitting section which transmits the new signature information to the signature verification device. The signature verification device receives the new signature information and verifies the delivery routes for all the items included in the selected item group based on the new signature information.