Ferroelectric thin films of 0.2BaTiO 3 -0.8BaZr 0.5 Ti 0.5 O 3 (BT-BZT) are dielectric materials applied in various sensors, particularly in capacitor manufacturing, due to their excellent electrical properties. This ferroelectric material also has a high dielectric constant value, such that it is suitable for use in Ferroelectric Random Access Memory (FeRAM) and microwaves. Therefore, this study aimed to synthesize thin BT-BZT films with annealing temperature variations of 700 °C, 750 °C, and 800 °C. To achieve this, the sol-gel method was applied to Fluorine Doped Tin Oxide (FTO) substrate, a selected technique for its simplicity and cost-effectiveness. The electrochemical properties were characterized using electrochemical impedance spectroscopy (EIS). The research results show that at a frequency of 100 Hz, the highest dielectric constant obtained was 58975.43 at a temperature of 800 °C. This temperature has the highest resistance compared to other samples. The highest capacitance value is 2.9 µF at a temperature of 700 o C. Therefore, it was concluded that the annealing temperature influenced the dielectric constant and the capacitance values of the capacitor.