The curable polyphenylene ether resin composition

PROBLEM TO BE SOLVED: To obtain a curable polyphenylene ether resin composition having excellent dispersibility of silica capable of forming a metal foil or the like pasted on the resin having excellent flatness free from aggregation of silica by compounding a silica treated with a specific silane coupling agent to a thermosetting polyphenylene ether based resin. SOLUTION: This thermosetting polyphenylene ether based resin composition includes (A) 100 pts.wt of a thermosetting polyphenylene ether based resin, (B) 10-38,000 pts of a silica treated with one or more kind of silane coupling agents selected from silane compounds having structure of formulas I-III (R1 and R2 are each a 1-5C divalent hydrocarbon). The composition preferably includes, (C) 1-1,900 pts of a hydrogenated block copolymer obtained by hydrogenating a block copolymer comprising a polymer block mainly comprising at least a vinyl aromatic compound and a polymer block mainly comprising at least a conjugated diene compound, per 100 pts of the component A.