Abstract: A dielectric ceramics possessing a high level of unloaded Q and low loss at high frequency beneficial for communications at high frequency is produced by a method which comprises heating a green compact of a composition represented by the general formula: xBaO.yMgO.zTa.sub.2 O.sub.5 (wherein x, y, and z satisfy 0.5.ltoreq.x.ltoreq.0.7, 0.15.ltoreq.y.ltoreq.0.25, 0.15.ltoreq.z.ltoreq.0.25, and x+y+z=1) to a temperature in the range of 1,500.degree. to 1,700.degree. C. at a temperature increasing rate of 100.degree. to 1,600.degree. C./minute and subsequently retaining the green compact at the temperature for not less than 30 minutes.