This article deals with the problem of the peculiarities of the study of crimes against faith in the archives of St. Petersburg. A brief analysis of the existing historiography on the problem under study is presented. The preserved material in the archives of St. Petersburg is considered. The author comes to the conclusion that a large amount of invaluable material on various crimes against faith is stored in the archives of St. Petersburg, which needs a comprehensive study. It is concluded that the analyzed material indicates a large number of various crimes committed in the Russian Empire in the XIX - early XX centuries.