The interior of the church contains the bodies of the martyred saints Flavia, Giustino, Gaudenzio and the bodies of the saintly children, Agrippina and Leonzio which were transported to Appignano under the pontificate of Pope Leo XII and Pius VIII. Also inside the church, there is a chapel with sacred relics called the Chapel of the Saints.
Its construction was authorised by Bishop Giovanni-Antonio Benvenuti on 29 March 1829 and it was begun in that same year on a design by Serafino Valentini of Macerata.
The Chapel contains five thousand relics placed in an artistic shrine designed by the aforementioned Valentini.
With a deed dated 24 November 1828, this sacred treasure, with the altar and the shrine, was donated to the Confraternity of Death by Father Vincenzo Benigni (1771-1846) from Appignano, canon of the Apiro Collegiate Church. Two imitations of a plaque are placed on the right and left sides of the Chapel of the Saints commemorating the event. The Chapel was inaugurated on 13 November 1831. Each year, for the entire month of May, the sacred relics are exhibited for veneration by many of the devoted faithful. 19th century. Serafino Valentini of Macerata