Light-transmissive epoxy resin composition and semiconductor device

A light-transmissive epoxy resin composition comprising (A) an epoxy resin, (B) a curing accelerator, and (C) an inorganic filler, wherein

• said composition satisfies both the relationships of the following formulae (1) and (2):
• [{2(nA2+nC2)−(nA+nC)2}/2]½<3.0×10−3 (1) [{2(fA+fC2)−(fA+fC)2}/2]½<1.0×10−5 (2)
• wherein nA is the refractive index at T1° C. of the cured product of the composition excluding the inorganic filler,
• nC is the refractive index at T1° C. of the inorganic filler,
• fA is a temperature coefficient of the refractive index of the cured product of the composition excluding the inorganic filler,
• fC is a temperature coefficient of the refractive index of the inorganic filler, and
• the temperature coefficient of refractive index is given by the formula (3):
• f={n(T2)/n(T1)−1}/(T2−T1) (3)
• wherein n(T1) is the refractive index at T1° C. and n(T2) is the refractive index at T2° C., with the proviso that T1<T2.