The church is in Piazza San Francesco and the facade is realized with alternated white alberese and serpentine bands. The left-hand side and the apse are on the other hand made of bricks. Built starting from 1281, it has a single nave that ends with three apse chapels with typically gothic ogiva vaults. At the beginning of the Twentieth century, a radical restoration erased almost completely works of art and furnishing that over the centuries had enriched the interior. Before the high altar there is the tomb slab of Francesco Datini, made by the Florentine Niccolò di Piero Lamberti. Other remarkable burial is that one of Gemignano Inghirami proposed of Saint Stephen and dead in 1460. On the side of the church there is a Renaissance cloister around which convent rooms are located. On the eastern wall an ogival arch leads to the Migliorati Chapel, entirely frescoed by Niccolo' di Pietro Gerini at the end of the Fourteenth century.