A crystallized epoxy resin which is easy to blend with a hardener or the like is a crystallized product of an epoxy resin derived from 4,4′-dihydroxy-3,3′,5,5′-tetramethylbiphenyl and an epihalohydrin, and the ratio of an endotherm between 50° C. and 130° C. to an endotherm between 80° C. and 125° C., measured by raising the temperature at a rate of 10° C. per minute using a DSC device, is 1.03 or more.