The present invention provides a polyester composition for a solar battery, which includes a dicarboxylic acid component having terephthalic acid as a main component and a diol component having ethylene glycol as a main component, the polyester composition satisfying the following Formulae (1) to (5): 0.65≦intrinsic viscosity≦0.90 (1); 0.7≦M/P≦1.3 (2); 200 ppm≦P≦600 ppm (3); amount of terminal carboxyl groups≦15 eq/t (4); and amount of terminal methoxy groups≦10 eq/t (5) (in the Formula (2), M represents the number of moles of an alkaline metal element and/or an alkaline earth metal element per 106 g of a polyester; and P represents the number of elemental phosphorus per 106 g of a polyester).