To obtain a phenolic novolak resin which exhibits relaxed crystallinity resulting from a mesogen structure of biphenyl and is easy to handle at its low melting point.

This phenolic novolak resin contains at least 65% of a compound represented by formula (2) (wherein (n) is 0) which is obtained by reacting a phenolic compound with one of isomers (excluding 4,4'-isomer) of formula (1) or a mixture of isomers of formula (1). In formula (1), X is a 1-4C alkoxyl group or a halogen group. In formula (2), R is hydrogen or a 1-4C alkyl group.