Method for producing an epoxy resin composition and a cured epoxy resin

PROBLEM TO BE SOLVED: To provide an epoxy resin composition that provides a homogeneous epoxy resin cured product having high electric insulation and thermal conductivity and that has excellent moldability.SOLUTION: The epoxy resin composition contains an epoxy resin having a liquid-crystalline unit including a mesogen group, a flexible unit bonded to at least one end of the liquid-crystalline unit, and a terminal epoxy group. The flexible unit is at least one group selected from the group consisting of the following formulae, wherein n is an integer of 4 or more.