In goods genuineness/counterfeit discrimination using IC tags, contradictory problems of the reliability and lifetime of the IC tags and the accuracy of goods genuineness/counterfeit discrimination are solved and circulation of a goods mounted with defective IC tags is prevented. A ratio of a number of IC tags having sent information indicative of the fact that the IC tags are mounted on the same object member to a number of IC tags from which the information is to be sent originally is determined and the genuineness/counterfeit discrimination is performed with the ratio. With regard to adopting combination of genuineness/counterfeit discrimination, information necessary for detection is added to a goods and information of the inspection area is stored in the IC tags. When the number of defective IC tags is large, a goods mounted with the IC tags is collected.