<p>A biaxially oriented film of polyethylene-2,6-naphthalate having a Young's modulus of at least 650 kg/mm<2> in a given direction on the film plane and a direction crossing it at right angles, the difference between the Young's moduli in the two directions being at most 200 kg/mm<2>, the difference between the thermal shrinkages in the two directions being 0 to 0.1 %.</p>
