In the coat of arms room (room n°18) there is a ceiling that was commissioned by the Duke of Savoy Amédée VIII in 1436, after a visit to Chillon castle during which he ordered a series of maintenance and beautification works. These are carried out by Aymonet Corniaux, the "maître des œuvres" (master architect) of the House of Savoy, whose mission was to maintain in good condition the properties of his lord.
In the Middle Ages, this room had a ceremonial function and was used in particular for the reception of prestigious guests. The first mention of a coffered ceiling appears in 1439 in the accounts of the castle. Made of resinous wood, it is divided into seventy-two compartments. The gaps between the master, secondary and tertiary beams create a very marked protrusion (more than one metre) which is reinforced by the superposition of mouldings. As a decoration, most of the wooden pieces are covered with grooves. This ceiling has many similarities with others on which Aymont Corniaux has worked (for example at the castles of Annecy and Ripaille). More generally, comparable ceilings can be found in buildings located in the medieval Savoy region (fortified house of Loche, priory of Talloires, castles of Montrottier and Menthon-Saint-Bernard). There are therefore particularities that make it possible to speak of a type of ceiling common to the cisalpine region at the end of the Middle Ages. Due to his long career (half a century!), Aymonet Corniaux has contributed to the development of this specific architecture. Finally, by frequently hiring local workers, he has also helped to disseminate this model.