Abstract: The invention provides a method of manufacturing polyesters which comprises an esterifying step wherein a dicarboxylic acid and a dihydroxyl compound are esterified and the next liquid phase polycondensation step wherein the resulting ester is subjected to liquid phase polycondensation in the presence of a polycondensation catalyst while a distillate which contains an reacted dihydroxyl compound and the polycondensation catalyst is distilled, wherein the distillate is subjected to a purification treatment comprising:(a) a distilling step;(b) a filtering step; and(c) a decoloring stepand then the thus purified distillate is recovered and supplied to the esterifying step. A further method comprises a purification treatment comprising:(a) a distilling step;(b) a depolymerizing step; and(c) a decoloring step.