Abstract: A novel CIEL device using a sintered multilayer ceramic substrate,consisting of a very high dielectric constant ceramic thick film insulating layer,Ag/Pd alloy in ternal electrodes and a ceramic base was prepared.The composition of the ceramic thick film was PbMg_1/3Nb_2/3O₃(PMN)-PbTiO₃(PT)-PbCd_1/2W_1/2O₃(PCW).The ceramic thick film and the internal electrodes were fabricated by casting tape process and silk-screen process,respectively.The ceramic substr ate was fabricated by the green sheet laminating technology and fired at a low sintering temperature,930~950 ℃.The relative dielectric constant and the loss for the ceramic thick film is more than 14000 and about 1% at room temperature.As a insulating layer for the CIEL devices,the figure of merit of the ceramic thick film with a value above 80 μC/cm²,is much higher than that of the ordin ary thin film insulators.Scanning e lectron microscopy (SEM) was used to investigate the morphology of the cross section of the substrate and the surface of the ceramic thick film.The CIEL device with ZnS:Mn as an active layer and Y₂O₃ as an upper insulator has a low threshold voltage of 41 V under 50 Hz sinusoidal wave voltage driving.