The central box gives a spectacular view of the horseshoe-shaped auditorium, which had to be completely rebuilt after the Second World War. Erich Boltenstern, a professor at the Technical University and the Academy of Fine Arts in Vienna, was awarded the privilege of redesigning the auditorium, the new staircases leading to the former third floor gallery, all public coat rooms, and the intermission halls in the upper levels. The architects Otto Prossinger, Ceno Kosak, and Felix Čevela took over the design of the intermission halls in the lower level. Van der Nüll and Sicardsburg’s original plan for the basic shape of the box theater with three tiers and two levels of open boxes (balcony and gallery) was retained.
The capacity of the auditorium is now 2,284 instead of the previous 2,881. It offers 1,709 seats, 567 standing spaces, 4 wheelchair spaces, and 4 wheelchair companion seats. The reduction of the number of spaces is due to stricter building codes and fire regulations. The reinforced concrete boxes were covered with wood for acoustic reasons, as the acoustics of the Vienna Opera House have always been of unprecedented brilliance. Some of the lateral upper tier seats with limited visibility were equipped with lamps for the purpose of reading the scores during the performance. The traditional colors of red, gold, and ivory were used for the auditorium, and the large central chandelier was replaced for safety by ring of built-in ceiling lights made of crystal glass. The glass ring weighs about 3,000 kilograms and uses 1,100 bulbs. It is 7 meters in diameter and 5 meters high; it has space for a lighting stand and corridors for maintenance of the system.
Rudolf Eisenmenger designed the iron curtain that separates the audience from the stage. It shows a scene from Gluck's opera “Orpheus and Eurydice”. In the spring of 1998, the State Opera commissioned the group “museum in progress” with creating a new picture for each season. This requires a specially developed process, which both guarantees the preservation of Eisenmenger's image, and shows the optimal quality of the newly created contemporary work. With the creation of contemporary museum space inside the Vienna State Opera, this traditional house shows its openness towards progressive artistic developments.
The orchestra pit is the nightly home to musicians from one of the most famous ensembles in the world: the members of the State Opera Orchestra, from which musicians for the Vienna Philharmonic are recruited. The orchestra pit, with 123 square meters of space, holds approximately 110 musicians.
For fire protection, there are three iron curtains: the main curtain which separates the stage from the auditorium, and two more to fireproof the side stages and the backstage. For additional protection, the previous wooden ceilings were replaced by reinforced concrete slabs. In place of the previous slate roof coupled with wooden shingles, a new fireproof, waterproof and windproof roof was built. This copper skin over a thin reinforced concrete shell was the original desire of architect Van der NüIl, and it was finally brought to fruition many years later.
Terraces were added on the top floor, creating not only additional escape routes, but also outdoor intermission areas during the warmer months. Since September 1999, the large terrace has been the home of another stage: the Mobilkom Austria tent for children.