A sticker having an IC tag comprises: an antenna portion; and an IC chip. The IC chip is connected to and joined with the antenna portion, and has a function of communicating via the antenna portion. The sticker having an IC tag is mounted on a container having a cover, and comprises a single-stroke line portion. The single-stroke line portion is connected to and joined with the IC chip, and is adhered to an upper surface of a cover portion of the container having a cover. The IC chip performs detection on disconnection of the single-stroke line portion.
