When a product attached with an ID tag is placed inside a package body, there is a risk that communication with an ID tag using a reader/writer is blocked. Then, it is difficult to manage products in a distribution process of products, which leads to lose convenience of ID tags. One feature of the present invention is a product management system that includes a package body for packing a product attached with an ID tag, and a reader/writer. The ID tag includes a thin film integrated circuit portion and an antenna, the package body includes a resonance circuit portion having an antenna coil and a capacitor, and the resonance circuit portion can communicate with the reader/writer and the ID tag. Accordingly, the stability of communication between an ID tag attached to a product and an R/W can be secured, and management of products can be conducted simply and efficiently, even if a product is packed by a package body.