To provide an epoxy resin composition in which even though the roughness of a roughened surface obtained by roughening the surface of a cured product of the epoxy resin composition is small, the roughened surface has a high adhesion strength to a plated conductor, and an insulating layer can achieve a low coefficient of linear expansion and a low dielectric loss tangent.

The epoxy resin composition includes an epoxy resin (A), an active ester compound (B), and a triazine-containing cresol novolac resin (C).