A dielectric porcelain composition of the present invention includes a first component and second component. If the first component is represented by the general formula of xBaO-yNd.sub.2O.sub.3-zTiO.sub.2-wBi.sub.2O.sub.3 (provided that x+y+z+w=100), x, y, z, and w satisfy 12.ltoreq.x.ltoreq.16, 12.ltoreq.y.ltoreq.16, 65.ltoreq.z.ltoreq.69, and 2.ltoreq.w.ltoreq.5, respectively. The second component includes 30 to 37 wt % of BaO, 33 to 46 wt % of SiO.sub.2, 8 to 12 wt % of La.sub.2O.sub.3, 3 to 7 wt % of Al.sub.2O.sub.3, 0 to 1 wt % of SrO, 0 to 10 wt % of Li.sub.2O, 0 to 20 wt % of ZnO, and 7 wt % or less of B.sub.20.sub.3. The compounding ratio of the second component is between 10 wt % and 30 wt % when the sum of the first and second components is 100. In addition, 0.1 to 1 parts by weight of Li.sub.2O and 3 to 10 parts by weight of ZnO, relative to 100 parts by weight of the sum of the first and second components, is also contained as a third component. An average particle diameter of the dielectric mixed powder forming dielectric porcelain composition before firing is 0.9 .mu.m or less.