It has 3,022 seats on its 1st, 2nd, and 3rd floors. On the 1st and 2nd floor seats, and on the wall of the 3rd floor, LCD monitors have been set up for the first time in Korea to provide subtitles and video. The theater is equipped with a state-of-the-art stereo system to deliver subtle sound evenly to all seats of the theater. In addition, there are a total of 102 battens that facilitate quicker stage changes and create a more dynamic stage. This is an international-level multi-purpose hall capable of presenting all kinds of genres. The number of seats 3,022 (1,030 seats on 1st floor/ 964 seats on 2nd floor/ 1,028 seats on 3rd floor)
The embossed statue in the front pillars of the theater was built over a period of 15 months by sculptor Kim Young-joong. Exhibited to the public with the opening of the Sejong Center, this sculpture is 11m in height, 6.75m in width, 45cm in thickness, and has 324 granite pieces of a size of 90cm×70cm×45cm. It is evaluated as the most tailored work in that the Sejong Center was designed as a representation of moving the classic into the modern.
Produced over a period of one year at Karl Suske in 1978, the overall shape was designed after the Korean traditional music instrument the Geomungo, while the Spanish trumpet pipe located at the upper center was also based on the Korean traditional architectural style Chuneo. In addition, a Buddhist bell was installed at the organ to produce a Korean sound. It consists of 98 settings and 8,098 pipes with a 6-step manual (keyboard) and pedal based keyboard that at the time of opening was Asia's largest instrument. It is currently recognized as a world class instrument.
The library, which has collected the historical traces of the Sejong Center, is located on the 3rd floor of the Sejong Grand Theater. It accumulates and store materials relating to performances and exhibitions of the Sejong Center.