To provide a pigment-containing polyester resin composition which is prevented from edge waving and excess neck-in when formed into a film and gives a film having a flat part with an increased width and a thickness varying little and improved in yield and adhesion to a substrate.

This resin composition is prepared by dispersing an inorganic pigment in a thermoplastic polyester resin and comprises 100 pts.wt. thermoplastic polyester resin, 0.5-150 pts.wt. ethylene polymer, and 250 pts.wt. or lower inorganic pigment.