There is provided an epoxy resin composition having low viscosity and a high cationic curing property. An epoxy compound of Formula (1): (in Formula (1), A is an (n4)-valent C4-20 linear hydrocarbon group optionally containing an epoxy group, an (n4)-valent C4-20 cyclic hydrocarbon group optionally containing an epoxy group, or an (n4)-valent group of a combination of the linear hydrocarbon group and the cyclic hydrocarbon group; R1 and R2 are each independently a hydrogen atom or a C1-10 alkyl group; n1 is an integer of 2 to 6; n2 is an integer of 2; n3 is an integer of 1; and n4 is an integer of 3 to 8). For example, A is an (n4)-valent organic group formed by removing (n4) hydrogen atoms from butane, pentane, or hexane, or an (n4)-valent organic group formed by removing (n4) hydrogen atoms from cyclobutane, cyclopentane, cyclohexane, epoxycyclohexane, alkyl-substituted epoxycyclohexane, bicycloheptene, or bicyclooctene.