Provided is a curable resin composition that exhibits good heat resistance and low thermal expansion, and that realizes good solubility in solvents, a cured product thereof, a printed wiring board including the composition, a novel epoxy resin that imparts these properties, and a process for producing the same. A curable resin composition contains, as essential components, an epoxy resin (A) having, in its molecular structure, a glycidyloxy group and a skeleton in which a naphthalene structure and a cyclohexadienone structure are bonded to each other via methylene group(s); and a curing agent (B).