The present invention provides a liquid-crystalline polyester having a structural unit represented by the formula (i), a structural unit represented by the formula (ii) and a structural unit represented by the formula (iii): wherein Ar1 is, at each occurrence, a member selected from the group consisting of a 2,6-naphthalenediyl group, a 1,4-phenylene group and a 4,4′-biphenylene group; and Ar2 and Ar3 are, at each occurrence, a member selected from the group consisting of a 2,6-naphthalenediyl group, a 1,4-phenylene group, a 1,3-phenylene group and a 4,4′-biphenylene group; wherein 40% by mole or more of all the groups Ar1, Ar2 and Ar3 are 2,6-naphthalenediyl groups; and wherein the polyester has a flow initiation temperature of from about 280 to about 320° C.