It is the first court verdict for the 76-year-old Nobel laureate since the army seized power on February 1, arresting her and blocking her National League for Democracy party from starting a second term in office.
She also faces trials on a series of other charges, including corruption, that could send her to prison for dozens of years if convicted.
The cases are widely seen as contrived to discredit her and keep her from running in the next election. The constitution bars anyone sentenced to prison from holding high office or becoming a lawmaker. Her party won a landslide victory in last November's general election. The army, whose allied party lost many seats, claimed there was massive voting fraud, but independent election observers did not detect any major irregularities.
Suu Kyi remains widely popular and a symbol of the struggle against military rule.
The army's takeover was met by nationwide nonviolent demonstrations which security forces quashed with deadly force, killing nearly 1,300 civilians, according to a tally by the Assistance Association for Political Prisoners. With severe restrictions on nonviolent protest, armed resistance has grown in the cities and the countryside to the point where U.N. experts have warned the country is sliding into civil war.
Suu Kyi, who received the Nobel Peace Prize in 1991 for her nonviolent struggle for democracy, has not been seen in public since being taken into custody on the day of the military's takeover. She has appeared in court at several of her trials, which are closed to the media and spectators. In October, Suu Kyi's lawyers, who had been the sole source of information on the legal proceedings, were served with gag orders forbidding them from releasing information.