To enable a process to obtain a biaxially oriented polyester film for a cathode ray tube which has good adhesion to a hard coat layer by forming an application layer on one side or the biaxially oriented polyester film in which haze and a longitudinal heat shrinkage percentage are specified.

A polyester film for a cathode ray tube which has an application layer on one side of a biaxially oriented polyester film in which haze is 2.0% or less, and a longitudinal heat shrinkage percentage after heat treatment at 100°C for 5min is 0.1-2.0%. The polyester film is made to contain particles to be slidable and to improve handling properties, and appropriate projections can be formed on the surface for the purpose. As the particles, inorganic particles of calcium carbonate, calcium phosphate, silica, kaolin, etc., crosslinked polymer particles, organic particles of calcium oxalate, deposit particles generated in the polymerization of polyester can be named.