Ba0.5Sr0.5TiO3 thin films were grown by rf-magnetron sputtering. Pt and RuO2 films were used as bottom electrodes of the Ba0.5Sr0.5TiO3 thin films. Further, a Pt/RuO2 hybrid electrode was adopted as an electrode for the film. Structural properties of the Ba0.5Sr0.5TiO3 thin films were found to be closely related to the type of the bottom electrodes. Dielectric constants of the films on Pt, RuO2, and Pt/RuO2 were measured as 500, 320, and 450 in the range of 100 Hz ˜ 1 MHz, respectively. Leakage current characteristics of the films were also found to be strongly dependent on the type of the electrodes and their microstructures.