This is a large room, with a gallery of 44 m². Little remains of Alfred Porteneuve’s original decor and furnishing, the room having undergone extensive alterations. Some of the decorative indirect lighting remains, in the form of “pot à feu” vases, which were very popular in the 1930s; these were made to look like bronze vases but are in fact painted tin.

The first meeting of the Council of the League of Nations, in September 1936, took place in this room, as the Council Chamber was not yet ready.

The appearance of the room changed completely following a modernization project begun in 1957, which involved removing some of the tiered seating and creating a gallery, installing interpretation booths, replacing the furniture and making alterations to the podium and the lighting.