Epoxy resin composition, cured product, and electrical or electronic component

An epoxy resin composition (A), comprising:

• 89.0% to 99.9% by mass of an epoxy resin (1) having a structure represented by formula (1) and
• 0.1% to 11.0% by mass of an epoxy resin (2) having a structure represented by formula (2) and/or
• an epoxy resin (3) having a structure represented by formula (3), each mass percent relative to 100% by mass of a total of the epoxy resin (1) and the epoxy resin (2) and/or the epoxy resin (3),
• wherein in formulae (1), (2), and (3):
• each X is independently a direct bond or a divalent linking group selected from the group consisting of —SO2—, —O—, —CO—, —C(CF3)2—, —S—, and a hydrocarbon group having 1 to 20 carbon atoms,
• each R1 is independently selected from the group consisting of a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a halogen element, and a ring structure having 4 to 20 carbon atoms formed with two R1 groups on adjacent carbon atoms of the cyclohexane ring,
• n is an integer of 0 to 2, and
• wherein an epoxy equivalent of the epoxy resin composition (A) is 176 to 186 g/equivalent.