The present invention relates to a polyester resin including at least one repeating unit represented by the following formula (1): ##STR00001## wherein Ar.sub.1, Ar.sub.2 and Ar.sub.3 independently represent a substituted or unsubstituted arylene group, a substituted or unsubstituted bivalent heterocyclic group, or a combination thereof; T.sub.1 and T.sub.2 each represent a linear or branched bivalent hydrocarbon group having 1 to 10 carbon atoms; and n represents 0 or 1.