This paper presents a self-shielded Yagi antenna with a rectangular horn for the 60 GHz unlicensed band. The rectangular horn is used for the isolation from the other electronics around the antenna. For the self-shielded Yagi antenna with a rectangular horn, a 28.5 % impedance bandwidth, a 33.3 % 3 dB-gain bandwidth, and a 12.7 dBi peak gain are achieved. To the best of the authors’ knowledge, the proposed 60 GHz self-shielded antenna shows the widest bandwidth characteristics among those that have been reported.