Wattana was charged in the court on April 19 that he had violated the Computer Crime Act by posting false information onto a computer network.
Public prosecutors alleged that Wattana posted on his Facebook wall on March 1 and 2 that the National Council for Peace and Order would not return the ruling mandate to the people.
The lawsuit said Wattana disseminate false information because the NCPO was making preparations to hold the next election, including holding a public referendum on the new charter.
Wattana and his legal advisor, Narinpong Jinapak, came to the court to listen to the verdict.
The court ruled that Wattana did not disseminate false information as charged but he simply expressed his sincere opinion.