A wholly aromatic polyester film, (A) which is made of a wholly aromatic polyester consisting essentially of the following recurring units I and II ##STR1## wherein the aromatic ring may be optionally substituted with at least one substituent selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a halogen atom and a phenyl group, said wholly aromatic polyetser comprising 10 to 90 mol % of the recurring unit I and 90 to 10 mol % of the recurring unti II, being capable of forming an optically anisotropic melt phase, and having a melt strength at a temperature 20.degree. C. higher than its transition temperature to liquid crystal of at least 2.0 g/mm.sup.2 ; (B) said film having an oxygen permeability of not more than 1.0 cc. 20 .mu./m.sup.2. day. atm at a temperature 20.degree. C. and a relative humidity 65%; and (C) said film having thermal shrinkages both in the machine direction and in a direction perpendicular thereto of not more than 1% at a temperature 250.degree. C. Said wholly aromatic polyester film can be produced by melt-extruding a wholly aromatic polyester to form into a film under conditions that a shear rate applied to the wholly aromatic polyester in a molten state at the exit of the molding die is not less than 500 sec.sup.-1.