NOVELTY - A polyethylene terephthalate type resin film has difference (( Delta )nab) of refractive index of direction which forms 45 degrees angle to winding direction of film and refractive index of direction which forms 90 degrees angle to winding direction of film is 0.015-0.060.    USE - A polyethylene terephthalate type resin film for optical use, solar cell use, minute printing use or single wafer use. Can also be used as base film for prism lens sheets, back lights, anti-reflective (AR) films, touch panel, near-infrared absorption film for front board of plasma display and light diffusing plate, optical film for optics, crushing prevention film for CRT, processing film, prism sheet, antireflection film and hard coat film for LCD, electromagnetic wave absorption film, and transparent conductive film for electroluminescence.    ADVANTAGE - The polyethylene terephthalate type resin film has outstanding processing characteristics and favorable permeability, planarity and cutting property, is excellent in heat shrinkage characteristics, and suppresses generation of spike.    DETAILED DESCRIPTION - A polyethylene terephthalate type resin film has difference (( Delta )nab) of refractive index of direction which forms 45 degrees angle to winding direction of film and refractive index of direction which forms 90 degrees angle to winding direction of film is 0.015-0.060. The breaking strength (TS) of direction which forms angle of 45 degrees , 135 degrees and 90 degrees to winding direction of film/breaking elongation (TE) ratio is 0.6-2.6 MPa/%. The length of width direction of film equally divided into 5 in film width direction of film is greater than or equal to 70 cm. The difference of maximum value and minimum value of HS150 when heated for 30 minutes at 150 degrees C is less than or equal to 0.1%. The HS150 of 5 samples heated at 150 degrees C is 0.0-0.5%. The difference of maximum value and minimum value of HS180 when heated for 30 minutes at 180 degrees C is less than or equal to 0.15%. The HS180 of 5 samples heated at 180 degrees C is 0.7-1.5%. The thickness coefficient of variation of winding direction of film is less than or equal to 6%. The thickness of film is 70-400 mu m. An INDEPENDENT CLAIM is included for a method of manufacturing polyethylene terephthalate type resin film.