The exhibits are kept in display cases as well as allow for the proper maintenance will also allow the possible use during special religious occasions.
The museum introduces the visitor directly access in the tower where the Roman funerary urn and some fragments of floor mosaic dating from the fifth or sixth century already testify to the existence in early medieval age of a building for worship. Then we come to the New Sacristy, built in the late fourteenth century and initially used as the courtroom, has a Crucifixion on the western wall of the painter Giovanni Christians. Here there are items of fourteenth-century goldsmith of great interest such as the  reliquary of St. Zeno , the  chalice  and  Sant'Atto cross . From the New Sacristy leads to the Old Sacristy that once housed the Treasury of St. James, famous not only for its wealth but also for the memory of Dante's sacrilegious theft of Vanni Fucci. Among the precious gifts intended for the patron saint of the city there is the reliquary of him dedi-cate, the famous masterpiece by Lorenzo Ghiberti and his workshop. Once you reach the first floor of the building meet the halls for the exhibition of liturgical furnishings. From the third room, the seat of the bishop's chancellery, the fire that broke out in 1641 destroyed most of the furniture.
Beyond the sopraportico the Cathedral from which the bishop could attend religious services without going into the cathedral you find the St Nicholas Chapel.
Particular for the type of construction it is adorned with a rare fresco cycle with  stories of St. Nicholas  and a  Crucifixion  of the late thirteenth century.
Precious ornaments are on display in other rooms of the first floor and among them the  reliquary of St. Bartholomew  that Cardinal Giulio Rospigliosi commissioned for the relic of the saint given to the city by Pope Alexander VII. Finally, the itinerary leads back downstairs where, since the fourteenth century, opened shops of the merchants.
The Museum organized the Chapter according to the state museum criteria has returned to the city a visit space and knowledge of great historical and artistic value.