Abstract: A dielectric material having a high dielectric constant, very low high-frequency losses and very high temperature stability is prepared in particular by sintering previously ground raw materials in an oxidizing atmosphere at 1450.degree. C. The molar composition of the raw materials is as follows: t, TiO.sub.2 ; x, SnO.sub.2 ; y, ZrO.sub.2 ; a, NiO; b, La.sub.2 O.sub.3 ; where t is between 0.9 and 1.1, x is between 0.1 and 0.4 moles, y is between 0.6 and 0.9, a is between 0.015 and 0.06 moles, b is between 0.01 and 0.1 moles with an addition of iron of 0.0035 mole in respect of one mole of TiO.sub.2 obtained, for example, from the use of steel equipment for the grinding operation. When x is in the vicinity of 0.35, the coefficient of thermal variation .tau..sub.f is reduced to zero and the quality criterion Q.f is high.