To provide a polyester resin excellent in transparency, heat resistance (particularly ≥110°C autoclave heat resistance), impact resistance, chemical resistance, gas barrier property and an ultraviolet light-protecting property and to provide a molded product thereof.

The modified polyester is obtained by carrying out polycondensation of 2,6-naphthalene dicarboxylic acid as a main acid component with three components of a bis[4-(hydroxyethoxy)phenyl]sulfone component, a 1,4-cyclohexanedimethanol and a 2-4C aliphatic glycol component as main glycol components each in a specific range.