A wholly aromatic copolyester composed mainly of isophthalic acid units and hydroquinone units, the total proportion of said isophthalic acid units and hydroquinone units being at least about 80 mole % based on the entire units, said wholly aromatic copolyester having a terminal carboxyl group concentration, measured by the method described in the specification, of not more than about 90 eq/10.sup.6 g and a reduced viscosity, determined at 35.degree. C. in a mixed solvent of phenol and tetrachloroethane in a weight ratio of 4:6 in a concentration of 1.2 g/dl of at least about 0.6 and being substantially linear and melt-shapable and substantially free from a halogen atom bonded to the molecular chain, and a film prepared therefrom by melt shaping.