His lawyer Sasinan Thamnithinan told AFP that his sentence was 60 years - a decade for each six Facebook posts he made but this was halved as he had pleaded guilty.
"It's broken the record," she said about the severe jail term. She further added that because Pongsak was arrested while Thailand was still under martial law there was no right to appeal the sentence passed by the military court.
Under Section 112 of the Criminal Code, anyone convicted of insulting the king, queen, heir or regent faces up to 15 years in prison on each count.
(Photo of Thailand's King Bhumibol Adulyadej and Queen Sirikit)