To obtain an aryl ester compound useful as an epoxy resin curing agent capable of giving cured products with both low dielectric constant and dielectric dissipation factor, and useful as a component of an epoxy resin composition.

This aryl ester compound is shown by formula I (Ar and Ar' are each a 6-20C aryl; P and Q are each H, a halogen, 1-10C alkyl, 5-10C cycloalkyl, 6-20C aryl or 7-20C aralkyl; Y and Z are each H, a 1-20C acyl, etc.; (g) and (h) are each 0-4; (m) and (n) are each 0-5; X is carbonyl, sulfone, CF2 or C(CF3)2). This compound is obtained by esterification of a polyhydric phenolic compound of formula II with a 1-20C organic acid (derivative) in the presence of a base. The other objective epoxy resin composition containing this compound is suitable as a resin for multilayered printed wiring boards for high-speed arithmetic processing or high-frequency telecommunication.