PROBLEM TO BE SOLVED: To provide an RF tag designed on the premise that an antenna is wound around a living thing. A ring-shaped RF tag body 1 according to the present invention is an RF tag designed on the premise that the ring-shaped RF tag body 1 itself is wrapped around a living thing such as an animal, and forms a ring state while being wrapped around the living thing. It includes an auxiliary antenna 10 and an annular feeding antenna 11 arranged at a position where the auxiliary antenna 10 having an annular shape is coupled to a magnetic field and connected to the IC chip 110. The annular RF tag body 1 according to the present invention can be applied to a wing band and a nose ring, and can also be in the form of a seal label. [Selection diagram] Fig. 1【課題】アンテナを生き物に巻くことを前提に設計したＲＦタグを提供する。【解決手段】本発明に係る環状ＲＦタグ体１は，環状ＲＦタグ体１そのものを動物などの生き物に巻くことを前提として設計されたＲＦタグで，生き物に巻かれた状態で環状を形成する補助アンテナ１０と，環状を形成した補助アンテナ１０と磁界結合する位置に配置されＩＣチップ１１０と接続している環状の給電アンテナ１１を備えている。本発明に係る環状ＲＦタグ体１は，翼帯や鼻環に適用でき，更には，シールラベルの形態にすることもできる。【選択図】図１
