The object of the present invention is to provide an epoxy resin composition for semiconductor encapsulation which is excellent in flowability, adhesion to substrates, flame retardancy and solder crack resistance without using bromine-containing organic compounds and antimony compounds. According to the present invention, there is provided an epoxy resin composition for semiconductor encapsulation characterized by including, as essential components, a phenolic aralkyl type epoxy resin having a biphenyl structure, a phenolic aralkyl resin having a biphenyl structure, a curing accelerator, an inorganic filler, a specific silane coupling agent having a secondary amine, and a specific silane coupling agent having a mercapto group.