The Vatican says former butler Paolo Gabriele stole a $100,000 cheque made out to the Pope.
Another man, identified as computer expert Claudio Sciarpelletti, has also been charged with complicity over the scandal that saw the leaking of confidential Vatican papers to an Italian journalist.
Gabriele faces up to six years in prison. The Vatican has said the trial will not take place until October at the earliest.
The 46-year-old butler was arrested during an investigation into the leak of private papal documents to the media.
He was held for 53 days in a Vatican cell before being put under house arrest in July to await the judge's decision.
The Vatican said after his arrest it found documents and copying equipment in Gabriele's home, revelations which shocked the close-knit Holy See community and saddened the aged pontiff.
The father-of-three is alleged to have photocopied and leaked top-secret emails and letters, taken from the desk of Georg Gaenswein, the pope's private secretary.
Gabriele told investigators he acted because he saw "evil and corruption everywhere in the church".
Vatican spokesman Federico Lombardi told journalists the investigation into a "wide and complex case" was not yet over and would continue to target others believed to be implicated.
Mr Lombardi said that computer expert Sciarpelletti had played a "marginal role" and could not really be considered an accomplice.
Gabriele's lawyers have denied media reports that their client was part of a wider whistleblowing operation aimed at shaking up the Vatican hierarchy.
There is a suspicion that he acted sincerely but was then manipulated as part of long-standing rivalries within the secretive Vatican administration.
"We don't think we have finished our work... The inquiry is still open with regard to other people who appear to be implicated," spokesman Lombardi quoted prosecutor Nicola Picardi as saying.
Gabriele, known as Paoletto, began working for the pope in 2006 and was one of a select few with access to Benedict's private chambers.
Under Vatican laws, a reprieve from the Pope could come at any moment during the investigation or trial, but religious observers say that while Benedict may offer his spiritual pardon, he is unlikely to interfere in the legal process.
The Vatican has been shaken by the scandal, which has drawn attention to divisions between senior clergymen in the Vatican and in particular growing criticism of the powerful secretary of state Tarcisio Bertone.
While the Vatican has officially reassured Bertone of its support and denied media reports of an internal power struggle, the embarrassment to the Church has been widespread and has taken a physical toll on the pontiff.
It is just the latest in a string of scandals which have plagued the Vatican in recent years, from allegations of money-laundering to clerical sex abuse.