Bangkok columnist and analyst Pravit Rojanaphruk was charged Tuesday with sedition and violation of Computer Crime Act for online postings concerning politics.
The lawyer for Pravit said his client acknowledged the charges at the police department's Technology Crime Suppression Division.
Pravit, currently a writer for Khaosod English, is very active on social media and outspoken in his criticism of the military regime.
Police announced last week that they would bring sedition charges against him and Watana Muangsook, the Pheu Thai politician. Sedition is punishable by up to seven years' imprisonment.
Both men had previously been invited for a meal and taken for attitude adjustment.
Pravit said on his Facebook page he faces two charges. One dates from February 2016, when he criticised the junta-drafted constitution.
The second case concerns Facebook posts from last month that criticised Prime Minister Prayut Chan-o-cha's handling of floods and the trial of ousted premier Yingluck Shinawatra.
"I have seen the content and I insist this an abuse of the sedition law," Pravit told reporters. "The law is being used to silence criticism on social media."
Rights group Amnesty International said the accusations against Pravit suggested there was "no end to the Thai authorities' determination to stamp out any form of criticism, whether online or on the streets".
Last month, the New York-based Committee to Protect Journalists announced that Pravit was a recipient of its 2017 International Press Freedom Award.