The parish, unlike the city, has an official document of its foundation. It was issued in Opatów on August 2, 1614, by the next owner of Ostrowiec, Prince Janusz Ostrogski, …
Due to the growing number of Ostrowiec residents, and thus the faithful of the parish of St. Michael, there was a need to build a larger church. This idea was taken up by Father Jan Naulewicz, the parish priest of St. Michael in the years 1902-1910. In 1904, he approached the architect engineer Stefan Szyller from Warsaw with a proposal to prepare a project to expand the existing church.