Baros, the top scorer at Euro 2004 but who in recent years was the target of fan abuse for a goal-scoring drought and his off-field antics, was expected to retire from the national team following the Czechs surprising run to the last eight.
The Czechs were sunk by a 79th-minute Cristiano Ronaldo goal in Warsaw on Thursday.
"After the team's elimination from the tournament, Baros announced in the changing room that he is finishing with the national team," the statement from the football federation said on Friday.
"The 30-year-old striker has been under sharp criticism for a long time, culminating in the first Euro match against Russia when he was substituted toward the end and some fans booed him."
While Baros bore the brunt of fan displeasure, the striker turned in a series of solid performances at Euro 2012 and was cheered by supporters in the match against Poland when he came off the pitch.
A bigger loss for the team would be captain Tomas Rosicky, who missed the Portugal game due to injury. The diminutive Arsenal midfielder and creative force behind the Czech attack said injuries were taking their toll and he was considering whether to keep playing for the national team.
"I would love to continue, but on the other hand I'm not the youngest anymore and have had problems with my fitness," he told Arsenal's website.
"I will take time to think about it. As I say, I would love to continue but I'm not stupid - I know I'm getting older and have to think about what is good for me."