The huge two-part door with gilded carving leads visitors to the first of the state halls in the palace, the Ball Room, or the Merchant Hall as it was also called before.
The windows and mirrors are decorated with carved and gilded frames and ormolu sconces. The sixteen painted tondi by the Italian artist Giuseppe Valeriani based on subjects from Ovid's Metamorphoses and Virgil's Aeneid embellish the piers. The parquet floor is inlaid with a pattern of large stars. The ceiling painting, Parnassus, executed after Tarsia's design, contributes to the glorification of Empress Elizabeth Petrovna as a patroness of the arts in Russia.
From the date of its creation, the Ball Room was used for formal receptions, dinners and balls. In the early 20th century major state assemblies were held there. The basic restoration work was completed in 1995.