The miniaturization and exponential growth of popular portable electronic device have created a stimulated interest and demand for compact and light power source devices. Especially thin film batteries have much demand for smart card, MEMS device, and small sensor. They can be fabricated various sizes and shapes on virtually any type of substrate. Rechargeable thin film battery has been developed with graphite, SnO2, and WO3 as anode materials and TiS2, MoS2, and V2O5 as cathode materials. In the cathode materials, metal oxides (LiCoO2, LiMn2O4, V2O5 etc.) have been focused because of high voltage, energy density, and easy handling. V2O5 represents one of promising cathode materials for use in rechargeable thin film batteries. The V2O5 has a higher volumetric capacity (495 Ah/L) and high voltage range (3.6-1.5 V)