SECURITY SYSTEM

PROBLEM TO BE SOLVED: To provide a security system which can be easily adopted even in a store where the number of sales products and the number of pieces to be sold are large, regarding the security system.SOLUTION: By periodically activating an RFID antenna 8 installed inside a store, stock management of merchandise present inside the store is performed, and a shoplifter is to be specified from persons leaving the store at the point of time occurrence of shoplifting. Thus, an equipment cost is suppressed since there is no need of installing the RFID antenna 8 for each merchandise, and as a result, the security system to be easily adopted even in a store where the number of sales products and the number of pieces to be sold are large can be provided.