Multilayered printed wiring board

A multilayered printed wiring board, comprising:

• a plurality of insulator layers, each formed of a glass cloth impregnated with an epoxy resin composition;
• a plurality of metal foil layers, in each of which a circuit is formed, the metal layers being laminated alternately with the insulator layers, each of the insulator layers being placed between two of the metal layers;
• and
• a cavity providing continuity between the metal foil layers alternately laminated with the insulator layers,
• wherein the epoxy resin composition comprises at least phosphate ester, aluminum hydroxide, silica, calcium oxide, strontium titanate, and iron oxide, and
• wherein inorganic components are provided in the insulator layers as about 8% to about 18% by mass of phosphorus pentoxide (P2O5), about 20% to about 28% by mass of aluminum oxide (Al2O3), about 0.1% to about 0.6% by mass of silica (SiO2), about 0.1% to about 1.0% by mass of chlorine (Cl), about 15% to about 20% by mass of calcium oxide (CaO), about 0.3% to about 0.5% by mass of titanium oxide (TiO2), about 0.2% to about 0.4% by mass of iron oxide (Fe2O3), and about 0.1% to about 0.3% by mass of strontium oxide (SrO), in converted values as measured by an X-ray fluorescence analysis.