Metamaterials (MMs) refer to a class of artificially engineered structures comprised of electric/magnetic resonant building blocks much smaller than the operating wavelength. The extraordinary electromagnetic responses of MMs, not available for naturally occurring materials, have attracted intensive investigations on the underlying physics as well as related applications. In recent years, MMs-based antennas are widely studied and proved to have great potential in improving the radiation performance. In this paper, a MMs-based Febry-Perot cavity antenna with wide viewing angle is proposed about 14 GHz. The antenna consists of a high-impedance surface which works as an artificial magnetic conductor (AMC) at resonance frequency and a partially reflective surface (PRS). The AMC loading contributes to the low-profile and high-gain property of the antenna, as the AMC ground plane gives a near-zero phase shift in contrast to conventional metal sheet ground plane. The lateral size of the antenna is only about 3λ × 0.6λ; and the thickness is about λ/5. Metal walls surrounding the limited aperture are introduced to prevent the leakage of cavity mode and improve the radiation pattern, which also protects the antenna from external electromagnetic environment. The MMs-based high-gain antenna has a broad beam width in H-plane, which may be applied in ETC and RFID system.