French academic Clotilde Reiss on Tuesday appeared before Tehran's Revolutionary Court and was then allowed to return to her country's embassy, the French foreign ministry said, AFP reported.
The 24-year-old Iran expert was arrested at Tehran airport on July 1 and charged with "collecting information and provoking rioters" during mass protests over President Mahmoud Ahmadinejad's re-election.
"She appeared before the judge and then came out and returned to the embassy," said foreign ministry spokesman Bernard Valero in Paris.
The Tehran court did not render a verdict in the case and French officials said they did not rule out yet another court appearance for Reiss, who was released on bail in August on condition that she remain at the embassy.
"We want her to be declared innocent and that she be allowed to return to France," added Valero.
Ahead of the hearing, France had demanded formal guarantees from Iran that it would not jail Reiss but allow her to return to the embassy while she awaited a verdict.
But Iran offered no such guarantees and said the French demands were unjustified.
Reiss was preparing to fly home after completing a six-month teaching and research assignment in the central city of Isfahan when in June she witnessed the mass protests, took pictures and emailed them to friends.
Scores of reformers, journalists and opposition supporters were jailed in a government crackdown and more than 140 have appeared in mass trials.
France has insisted that Reiss is not guilty and has demanded her unconditional release.
President Nicolas Sarkozy in September rejected as "blackmail" a tit-for-tat offer from Iran to release Reiss if France reciprocates by freeing Iranian prisoners including Ali Vakili Rad, convicted for the 1991 murder in Paris of Shapour Bakhtiar, Iran's last prime minister under the shah.
The arrest of Reiss has stoked tensions between France and Iran, which already are at odds over Tehran's nuclear programme and Paris' harsh criticism of the regime's crackdown on opposition protesters.