The church is a single-nave building, and on the sides of the main altar are two small chapels in slight wall recesses, with smaller altars along the walls. A crucifix which he used on his missions is preserved here, to the left of the sanctuary. St. Leonard's cell has been turned into a museum. The left
side altar contains the relics of St Flavianus, a martyr. The altarpiece shows St. Francis of Assisi. The right side altar contains relics of St. Colomba, and the altarpiece depicts St. Anthony of Padua. Above the front altar on the right side wall is a crucifixion scene by
Giovanni Battista Benaschi from the 17th century, above the rear altar on the right is the depiction of Saints Paschalis, Diego and Salvatore d'Orta, a work by
Giacinto Calandrucci. On the centre wall are the relics of Blessed John Baptist of Burgundy. On the left side wall at the front is an altar with a representation of the Archangel Michael, also by Benaschi. The rear altar on the left contains an altarpiece showing the
Annunciation of the Lord, again by Benaschi. Painter
Francesco Mancini (1679–1758) is buried in the church; as is Cardinal
Silvio Valenti Gonzaga (†1756). ==References==