Peter H. Gilmore
Peter H. Gilmore is the administrator of the Church of Satan, and has been on shows such as The History Channel, The Sci-Fi Channel, and Point of Inquiry, which refers to him as the High Priest of the Church of Satan. He is a LaVeyian Satanist, thus he is an atheist as well.
Gilmore writes(and has written since 1989) a journal called "The Black Flame". In 2005 he also wrote an introduction the The Satanic Bible, which was intended for the teenage crowd. In 2005 his essay on Satanism was also published in the Encyclopedia of Religion and Nature, under LaVeyian/non theistic satanism.
He authored The Satanic Scriptures, a collection of his essays and observations.