PURPOSE: To provide dielectric porcelain having a high dielectric constant, a small dielectric loss, a high dielectric breakdown voltage, and high insulation resistance.

CONSTITUTION: Dielectric porcelain is composed of a composition expressed by a formula: X[(BaO)(1-k-m-n)(MgO)k-(CaO)m(SrO)n].yTiO2.zLaO3/2, wherein barium oxide(BaO) is substituted with magnesium oxide(MgO) or the like at substitution ratios (k), (m) and (n), e.g. within a range of 0.001≤(k)≤0.100 in the case of MgO; and (x), (y) and (z) represent molar ratios, x+y+z=1 and (x), (y) and (z) range within an area surrounded by lines connecting points (a), (b), (c) and (d), wherein (a): x=0.430, y=0.525, and z=0.045; (b): x=0.475, y=0.490, z=0.035; (c): x=0.490, y=0.505, z=0.005; and (d): x=0.450, y=0.545, z=0.005. The dielectric porcelain includes 0.01-1.00 parts by weight of a manganese compound calculated in terms of MnO2 as an auxiliary component.