To provide a polyester stretched film without losing strength, transparency, heat resistance, barrier property, etc., equipped with a good tearing property and processability, and useful as packaging film, film for tape, a PTP package, an opening port of a beverage pack, or an exterior material of a gum or candy, inexpensively.

This easily tearable biaxially stretched polyester-based film excellent in processability is characterized by having 400 (GPam2) ET2 in its E (GPa), initial elastic modulus in longitudinal direction and T (m), thickness, and also 70 N both of lengthwise and sidewise directional end-tearing resistance values.