Initially the church was closely connected with the Poor Clares convent founded in 1225. It was only with the beatification of Sister Mattia, in 1765, that the building acquired its present name. Following the earthquake of 1740, the building was completely reconstructed on a design by the architect Gaetano Maggi, assisted by Domenico Valeri, maintaining the traditional division found in Poor Clare churches with a hall that is accessible to the faithful and another that is reserved for the nuns. It consists of a single chamber with camorcanna barrel vaulting. In the higher section there are four carved and gilded choirs by Antonio Politi, who also created all the other wooden elements. The interior is lined with columns in scagliola and beneath the high altar a glass case contains the body of Blessed Mattia. The plastered brick façade is divided into two superposed areas divided by a jutting trabeation ledge.