a dielectric ceramic composition having a high relative dielectric constant a high quality factor and a small temperature coefficient of resonance frequency , consisting essentially of calcium oxide , strontium , oxide , bismuth oxide and titanium oxide , and having a composition represented by the formula : . sub . a .. sub . b .. sub . c .. sub . d wherein 0 ≦ a & lt ; 30 , 0 & lt ; b ≦ 20 , 10 ≦ c ≦ 50 , 40 ≦ d ≦ 80 , and 0 & lt ; a + b ≦ 30 by mol %. this composition may contain at least one of thallium oxide , yttrium oxide and manganese oxide and at least one of germanium oxide , zirconium oxide , tin oxide , cerium oxide and hafnium oxide .