There is provided a polyester-based primer composition including 100 parts by weight of a polyester resin, 1 to 20 parts by weight of water-dispersible particles, and water as a remainder. Since a polyester-based primer composition of the present disclosure is excellent in water resistance and solvent resistance differently from a urethane primer composition, the polyester-based primer composition may obtain sufficient adhesive strength between a protection film and a functional coating layer even without assistance from additives such as a cross-linking agent, and may retain stable adhesive strength for a long period of time.