To provide an epoxy resin composition having high gas barrier properties and corrosion resistance in addition to excellent performances that epoxy resins originally have.

The gas barrier epoxy resin composition comprises an epoxy resin and an epoxy resin curing agent, wherein the halogen content of the epoxy resin is ≤0.6 mass%, the epoxy resin and/or epoxy resin curing agent has a skeletal structure represented by general formula (1) within a molecule, and the content of the skeletal structure represented by general formula (1) in the resin composition is ≥30 mass%.