A monolithic capacitor having a dielectric ceramic body cosintered with at least two base metal electrodes. The ceramic body is composed of a major ingredient expressed by the formula,(1-.alpha.){(Ba.sub.k-x-z M.sub.x L.sub.z)O.sub.k (Ti.sub.1-y R.sub.y)O.sub.2-(y/2) }+.alpha.CaZrO.sub.3where M is either or both of magnesium and zinc, L is either or both of calcium and magnesium, R is a rare earth element or elements, and .alpha., k, x, z and y are numerals in specified ranges. To this major ingredient is added a minor proportion of an additive ingredient. The additive ingredient is a mixture of boric oxide or lithium oxide, silicon dioxide and at least one metal oxide selected from among barium oxide, strontium oxide, calcium oxide, magnesium oxide and zinc oxide. For the fabrication of capacitors the mixture of the above major ingredient and additives in finely divided form are formed into moldings of desired shape and size, each with at least two electrodes buried therein. The moldings and electrodes are cosintered in a reductive or neutral atmosphere at temperatures of less than 1200 degrees C. and then are heated at a lower temperature in an oxidative atmosphere.