Epoxy resin composition for encapsulating semiconductor, semiconductor device, and mold releasing agent

A semiconductor device comprising a copper-containing lead frame and a semiconductor element,

• wherein the semiconductor element is encapsulated with a cured product of an epoxy resin composition for encapsulating a semiconductor,
• wherein the epoxy resin composition comprises an epoxy resin (A), a curing agent (B), an inorganic filler (C), and a mold releasing agent,
• said mold releasing agent contains a compound (D) having a copolymer of an α olefin having 28 to 60 carbon atoms and a maleic anhydride esterified with a long chain aliphatic monohydric alcohol having 12 to 22 carbon atoms;
• the compound (D) contains the copolymer of α-olefin having 43 to 60 carbon atoms and a maleic anhydride esterified with a long chain aliphatic monohydric alcohol having 12 to 22 carbon atoms;
• and
• a content of said compound (D) having the copolymer of α-olefin having 28 to 60 carbon atoms and maleic anhydride esterified with the long chain aliphatic monohydric alcohol having 12 to 22 carbon atoms is equal to or more than 55% by mass and equal to or less than 100% by mass, based on 100% by mass of the total amount of said mold releasing agent.