To provide an epoxy resin composition which excels in heat resistance to soldering and, has good moldability, and to provide a semiconductor device using the same.

The epoxy resin composition comprises, as the essential components, (A) an epoxy resin, (B) a phenolic resin, (C) a benzoxazine to be represented by the formula (wherein R1 is a hydrogen atom or a 1-4C alkyl group; and R2 is a 1-4C alkyl group or a phenyl group), (D) an amine based curing accelerator, and (E) an inorganic filler at a compounding ratio of the above phenolic resin (B) to the above benzoxiazine (C) of 20:80 to 95:5. The semiconductor device uses this epoxy resin composition.