Don Mueang International Airport's newly-opened Terminal 2 was busy only hours after the opening.
The terminal, reserved for domestic flight check-in, is opened ahead of heavy traffic during the New Year holiday period.
It is equipped with six check-in rows and 11 baggage scanners which are able to handle 1,800 bags per hour.
Four airlines are now operating at the terminal - Nok Air, Thai AirAsia, Lion Air, Thai Smile.
Terminal 1 is now only for international flight check-in. Both terminals will allow Don Mueang to accommodate 30 million passengers per annum.
Airports of Thailand which operates the airport plans to close parts of Terminal 1 for renovation. On March 8, 2016, the building will turn 102 years old.