The main altar was commissioned by Cardinal Nereo Corsini to the architect Nicola Salvi in 1739. The top of the altar rests on an urn in porphyry rosso antico, with an opening covered by an ornate bronze grating behind which are the relics of St Eustace and his wife Theopista, with their sons Agapitus and Theopistus. The altar is backed by a low screen in polychrome marble, upon which are a set of matching bronze candlesticks and a crucifix. A pair of impressive bronze candelabra featuring angels flank the steps.