The altarpiece is an ancient icon of Our Lady. The icon is a work of Roman school from the last quarter of the 13th century. The painting was made in oil and has undergone numerous alterations and restorations over the centuries. It is an image-shrine where in a small wooden oval placed at the heart of the Virgin holds the relics of the Forty Martyrs, of Pope st. Felix, of Saints Marco and Marcelliano.

(Another photo of the altarpiece here)