An object of the present invention is to provide an epoxy resin composition that provides, when used for an insulation layer of a multilayer printed wiring board, a multilayer printed wiring board which is excellent in plating adhesion, heat resistance and moisture resistance reliability and capable of forming fine wiring. Another object of the present invention is to provide a resin sheet, a prepreg, a method for producing a multilayer printed wiring board, a multilayer printed wiring board and a semiconductor device.These objects are achieved by an epoxy resin composition comprising (A) an epoxy resin, (B) a phenoxy resin having a specific bisphenol acetophenone structure and (C) a curing agent, wherein the content of the phenoxy resin (B) is 10 to 30% by weight of the total solid content of the resin composition.