It is dedicated to Maria Assunta and rises in piazza Antonelli. It was built from 1666 and completed in mid 1700s.
The structure is a Latin cross with thwack vault and cupola on the transept, richly decorated with baroque stuccoes and eighteenth-century drawings, these last ones are the work of brothers Giovanni from Varese and Bianchi from Milan. Of particular value are : the main altar made of polychrome marbles and bronze, designed by Benedetto Alfieri in 1763; The grandiose canvas on the back wall of the choir, the work of 1745 of Giuseppe Antonio Pianca; the frescos of Giovanni Antonio De Groot in the chapel of Saint Francesco Saverio. In the side chapels can be noticed frescoes and paintings of 1779-1782 of the Perracino Family, statues of Ardia and Sella and a Christ of 1400s.
In the old oratory of the Brotherhood of Saint Marta, behind the chapel there are kept interesting frescos of 1543 of Giulio from Milan. The façade is the work of the engineer from Milan Carlo Federico Pietrasanta.