The Museum, founded in 1945, is located in Piazza del Duomo, inside the former Church of Jesus, and collects various objects and works of art from the churches of the territory belonging to the diocese. The art collection was founded in 1945 and contains important works by Pietro Lorenzetti, Beato Angelico, Bartolomeo della Gatta, Sassetta and Luca Signorelli, as well as sacred furnishings of considerable value. The exhibition starts from the only ancient object present, of very high quality, the Roman sarcophagus with the Combat between Dionysus and the Amazons, dating back to the second century A.D. and found near the Duomo.
The refined "Annunciazione del Beato Angelico" and among the works of the Master Luca Signorelli surely noteworthy is "Il Compianto di Cristo morto" painted in 1502 for the high altar of the Church of Santa Margherita, work of great plastic strength and lively colours.
Prestigious is the splendid Assunta che porge la cintola a San Tommaso work of Bartolomeo della Gatta, dated to the first seventies of the fifteenth century.