The present invention discloses a curable composition comprising: an epoxy compound represented by the following Formula (1); and one selected from the group consisting of: a thermal cationic polymerization initiator, an acid anhydride-based curing agent and a curing accelerator, and a photo-cationic polymerization initiator as well as the cured product therefrom. The above described curable composition is useful in that it allows for the production of a cured product having a high heat resistance. (In the Formula (1), A represents CR17R18; B represents CR19R20; R1 to R20 each independently represents a substituent selected from the group consisting of a hydrogen atom, an alkyl group and an alkoxy group; and n represents 0 or 1, with the proviso that when n is 0, m represents 1, and when n is 1, m represents 0.)