At a special session of Congress on Wednesday, after the playing of the national anthem, Temer was sworn in, Xinhua news agency reported.
He was surrounded by the president of the Supreme Court, Ricardo Lewandowski, the president of the Senate, Renan Calheiros, and the president of the Chamber of Deputies, Rodrigo Maia.
Temer will serve as president until December 31, 2018.
The new president did not make a speech but has already recorded an address to be broadcast live to the nation.
Temer twitted on his account, saying that “I swear to uphold, defend and fulfill the Constitution, observe its laws, promote the well-being of the Brazilian people, sustain the union, integrity and independence of Brazil.”
After the swearing-in ceremony, Temer was set to host his first cabinet meeting as full president.
After this, he is to fly to China, where he will participate in a number of events, culminating in the G-20 Summit, to be held in Hangzhou on September 4- 5.