The present invention is a thermosetting epoxy resin sheet for encapsulating a semiconductor, characterized by being a sheet formed from a composition including: (A) a crystalline bisphenol A type epoxy resin and/or a crystalline bisphenol F type epoxy resin, (B) an epoxy resin that is non-fluid at 25° C. other than the component (A), (C) a phenol compound having two or more phenolic hydroxy groups in a molecule thereof, (D) an inorganic filler, and (E) an urea-based curing accelerator. The present invention provides a thermosetting epoxy resin sheet for encapsulating a semiconductor that has excellent flexibility and good handleability in an uncured state, together with excellent storage stability and formability.