results of the measurements and the x y z a u03b1 u03b2 t w a and l values of the composition are given in table 1 in the composition according to the present invention ba 1 x sr x o a ti 1 y zr y o 2 is one mole u03b1 and u03b2 are mole and w is weight based on 100 weight of ba 1 x sr x o a ti 1 y zr y o 2 c the relative dielectric constant u03b5 s is particularly high when the composition is such that the percentage change of capacitance u03b4c c depending upon temperature is within u00b1 15 d the dielectric loss tan u03b4 is in the range of from 0 1 to 1 2 and is low e the percentage change of capacitance u03b4c ag c after 1000 hours aging at room temperature is within 10 and low f the percentage change of relative dielectric constant u03b4c dc c when the direct electric field of 750 v mm is applied is within u00b1 10 and is low when 34 x y 1 7 u03b1z 34 is less than 0 002 the percentage change of relative dielectric constant u03b4c c depending upon temperature becomes high c f no 3 when 34 x y 1 7 u03b1z 34.