Exorcism
In Catholic practice the person performing the exorcism, known as an exorcist, is an ordained priest. The exorcist recites prayers according to the rubrics of the rite, and may make use of religious materials such as icons and sacramentals. The exorcist invokes God—specifically the Name of Jesus—as well as members of the Church Triumphant and the Archangel Michael to intervene with the exorcism. According to Catholic understanding, several weekly exorcisms over many years are sometimes required to expel a deeply entrenched demon.
Exorcist
The Catholic Church's Rite of Exorcism was revised in 1999. Paragraph 13 of its introduction states that a priest can be appointed by the local Bishop either for a single act of exorcism, or to the permanent position of 'exorcist'. The Rite then specifies that whenever it uses the word "exorcist" without qualification, it indicates a priest mandated in this way.
Among notable exorcists, Gabriele Amorth served as chief exorcist of the Diocese of Rome; he was the founder of the International Association of Exorcists.