This paper presents the structure and process technology of simple and low-cost wafer-level packaging (WLP) forthin film radio frequency (RF) devices. Low-cost practical micromachining processes were proposed as an alternativeto high-cost processes, such as silicon deep reactive ion etching (DRIE) or electro-plating, in order to reduce thefabrication cost. Gold (Au)/Tin (Sn) alloy was utilized as the solder material for bonding and hermetic sealing. Thesmall size fabricated WLP of 1.04×1.04×0.4 mm3 had an average shear strength of 10.425 kg/mm2, and the leakagerate of all chips was lower than 1.2×10-5 atm.cc/sec. These results met Military Standards 883F (MIL-STD-883F). Asthe newly proposed WLP structure is simple, and its process technology is inexpensive, the fabricated WLP is a goodcandidate for thin film type RF devices.