Late on Sunday, Brazil's lower house lawmakers voted in favor of impeaching the president, sending the vote to the upper chamber known as the Federal Senate.
"Not resorting to the softer characteristics, I believe that this is a coup d'etat," Carmona, who is also a member of the Front for Victory faction, said.
The parliamentarian also noted that he was "embarrassed" with the voting process against Rousseff.
"It was an absolutely shameful act with the lawmakers in the lead roles, who turned such a delicate and important event, as the removal of the president from office into the trial over a person. This is very far from how the normal legal procedure should look like," Carmona stressed.
The Brazilian opposition has accused the president of corruption and of violating financial rules by manipulating state bank accounts to close budget gaps.
Earlier in the day, Rousseff said the impeachment proceedings lacked any legal grounds, vowing to continue her fight to retain her post.