Abstract: SrTiO₃/Ta₂O₅ doubly stacked dielectric layers with a total thickness of 530 nm to 730 nm were prepared by rf and dc reactive magnetron sputtering.The relative dielectric constant was measured to be 48 to 73 and the ΔV_y which reflects the loss tangent ranges from 0.06 V to 0.15 V at 500 Hz.The breakdown field strength is between 106 MV/m and 139 MV/m.The forward and reverse leakage current density is between 10^-9 A/cm² and 10^-7 A/cm² at an applied field of 0.05 V/nm,and the figure of merit is higher than 5 μc/cm².The dielectric properties of the doubly stacked dielectric layers are also compared with single SrTiO₃ and Ta₂O₅ thin films.The doubly stacked dielectric layers were applied to the inorganic TFEL devices with ZnS: Mn and Zn₂Si_0.5Ge_0.5O₄: Mn thin film phosphor.And suitable threshold voltage and high luminance are achieved.