The article focuses on the importance of religious architectural monuments for the spiritual, cultural and social life of the city and its inhabitants. There are highlighted the problems of using investment mechanisms to finance restoration works at these historical sites. The analysis of the ethnic and religious diversity of the population in the Astrakhan region is carried out, the significance of the Persian Mosque for the Muslim society is substantiated. On the basis of archival documents, the history of the mosque creation, its main architectural and structural characteristics, as well as the history of the mosque exploitation in the XX century are studied. The analysis of the current state of the Persian Mosque, measurements and photofixation were carried out, the defects in structural and decorative elements were revealed, and a conclusion about the unsatisfactory condition of the monument was made. According to the studied material on ancient and modern religious buildings, there has been developed a concept for the integral reconstruction of the Persian Mosque building including solutions for the reconstruction of lost parts and elements of the building, such as a hemispherical dome and four minarets at the corners of the building, as well as a general concept of retaining the original look of the object, taking into account all the legislation requirements for working with cultural heritage objects. A project of reconstructing and upgrading the inner yard of the mosque has been developed. The author’s definition of the term ‘revitalization’ regarding the object of cult architecture has been given as the revival of the object, preservation of its original functions and their expansion taking care both to the object and its mission. The types of financing the restoration works on similar objects include calling for funds of religious organizations and associations, citizens, as well as funding from municipalities and/or federal authorities, using the federal targeted programs or subventions. There are offered the alternatives of using the monuments of religious architecture: for their intended purpose, as objects of pilgrimage in religious tourism, objects of sightseeing and cultural education.