Paris, France - The charges, which also include claims of illegally prescribing drugs, were filed by France's professional pharmaceutical association and two women who accuse the Scientologists of bringing about their financial ruin.
One woman claimed she was psychologically pressured into paying thousands of pounds for lessons, books, drugs and a device called an "electrometer" which the church says can measure a person's mental state.
The church's main structure in France, the AGES-Celebrity Centre, and its bookshop face charges of "organised fraud", along with seven of its leaders.
The seven, including Alain Rosenberg, 60, the manager of the AGES-Celebrity Centre, face a maximum million-euro fine and ten year jail term if convicted. The church itself faces a five million-euro fine and closure.
The case has taken ten years to come to court.
Scientology is not banned in France but has been considered a sect since 1995.
It is a recognised religion in the United States, where it was founded in 1954 by L. Ron Hubbard, the science fiction writer. Followers include Hollywood stars Tom Cruise and John Travolta.
This is only the second time the church itself has been targeted in France. All other trials have been of individuals.
One of the female plaintiffs, Aude-Claire Malton, was allegedly approached by Scientologists in a Paris street in 1998 and offered a personality test, which, according to the prosecution were "void of scientific value". The Scientologists' sole aim, they argued, was to "claim their fortune" by "exercising a psychological hold" over her.
The 33-year old was allegedly gradually persuaded to hand over around £20,000 on books, communication and "life healing" lessons, as well as "purification packs".
Three other former Scientologists retracted their complaints after reportedly reaching an out-of-court financial settlement with the church.
One reportedly received 33,000 euros (£29,000).
The Church of Scientology said: "It's a trial for heresy: this could only happen in France... Let people choose their own path." The body's lawyer, Patrick Maisonneuve, said that all organisations contained "lost sheep" – including the Catholic Church – but "the only question in this trial is: was there embezzlement – certainly not whether Scientology is a religion or not".
The trial runs until June 10.
The Church of Scientology has powerful supporters in the US, notably Tom Cruise, the film star, who discussed his beliefs with Nicolas Sarkozy when he was still interior minister in 2004. Their meeting took place two months after the end of the embezzlement investigation.
Controversy erupted last year, when President Sarkozy's private secretary, Emmanuelle Mignon, said that sects in France were a "non-problem" and said that the Church of Scientology should be allowed to "exist in peace".