Built where a small Medieval oratory once existed, it was created to fulfil the wish of the notary Francesco Bo in 1576, when the Compagnia dei Disciplinati di S. Giuseppe was born, which later on took the name of Confraternity of the Holy Spirit. Once finished, in 1593, it was consecrated a year later and presents three naves, where the central one is double sized compared to the other two. The oratory was decorated at the end of the 17th century with rich stucco works by Giovanni Martello from Varallo Sesia for the two singers’ galleries, by Bernardino Barca for the whole cycle in the presbytery and by Domenico Dossa for the walls of the oratory. The artists Domenico and Michele Dossa realised the majestic ancon, created between 1697 and 1699, which constitutes the altar piece, and in the central niche there is the wooden polychrome statue of St. Joseph, sculpted after the plague in 1630 and brought to the church on 11 August of the same year. On the walls there are interesting masterpieces by Giovanni Battista Tagliasacchi, who from 1722 to 1727 realised the Passage of St. Joseph above the right singers’ gallery, the Rest during the Flight into Egypt on the counter-façade above the side door on the right, and the Visitation above the side door on the left. From 2004 to 2007 the oratory has been radically restored both on the inside and the outside, with funds from Banca di Piacenza.