The altar was designed by Pietro da Cortona and built by Giuseppe Rusconi. The small tabernacle over the altar consists of alabaster, agate, lapis lazuli, and its door of solid silver is adorned with precious stones and with a silver gilt portrait of the Risen Savior. A gilded bronze urn from 1637 by Alessandro Algardi underneath the altar holds the body of St. Ignatius Loyola.

(Another photo of the urn here)