The Oratory, built about 15th century as a devotional and welcoming space for the members of the Brotherhood of Santa Chiara, stands next to SS. Nazario and Celso church. The aisleless layout of the period, with a saddle roof, has a marble major altar dating 1582, surmounted with a niche housing a wooden statue of Santa Chiara. On the sides of the altar there are the marble statues of Saints Peter and Paul.

In the aisle, on the right, an altar devoted to Our Lady of the Snow, with a precious alabaster image and, on the left the altar of St. Isidore, patron saint of farmers. The interior walls are decorated with twelve terracotta statues of the Apostles. The wooden stalls of the council date back to the 17thh century and the Prior central seat is characterized by an archaic feisty bestiary. Inside the Oratory are celebrated the religious services of the Death Novena and the feasts of the Brotherhood Patron saints: S. Chiara, August 12th and St. Isidore, May 15th.