To provide an epoxy resin composition excellent in balanced soldering resistance and gate break property.

The epoxy resin composition is used for semiconductor device encapsulation, and comprises an epoxy resin (A), a hardener (B) and a silane coupling agent (C) wherein a silane coupling agent having a pH of an extracted water obtained by treating the silane coupling agent for extraction of not less than 3.5 and not greater than 4.7 is used for the silane coupling agent (C). An epoxy resin molding compound of the present invention is constituted by mixing and/or melt-kneading the above described epoxy resin composition. A semiconductor device of the present invention is constituted by encapsulating a semiconductor element with a hardened material of the above described epoxy resin molding compound.