One of major objects of the invention is to provide an epoxy resin composition and a semiconductor device exhibiting good soldering resistance when being formed on a non-copper frame. Thus, this invention provides an epoxy resin composition for encapsulating a semiconductor comprising (A) an epoxy resin, (B) a phenolic resin, (C) a hardening accelerator, (D) an inorganic filler and (E) a triazole compound, preferably an epoxy resin composition for encapsulating a semiconductor wherein the triazole compound is a compound represented by general formula (1): wherein R1 represents hydrogen atom, or mercapto group, amino group, hydroxyl group or a hydrocarbon chain with 1 to 8 carbon atoms containing one or more of the functional groups as an end group.