The assembly opened after agreement in mid-October on a transitional charter to help guide the Sahel nation back to elections.
A dozen members of the last parliament were among those appointed, including Abdoulaye Soma, who ran for president in 2020, and 41-year-old law professor Ousmane Bougouma, who was elected speaker on Friday.
Coup leader Captain Ibrahim Traore named 20 of the new deputies and the armed forces 16. The country's 13 regions selected one member each, civil society groups 12 and political parties 10.
"Our country, Burkina Faso, is living through difficult times in its history," Bougouma told the assembly.
"It's not a time for celebration but rather commitment and self-sacrifice," he said.
Traore, 34, ousted Lieutenant-Colonel Paul-Henri Sandaogo Damiba on September 30.
Traore has been appointed transitional president with the declared aim of taking pack huge swathes of territory held by "hordes of terrorists."
One of the world's poorest countries, Burkina has been struggling with a jihadist offensive since 2015.
Thousands have been killed in Burkina over the last seven years, around two million people out of a population of 21 million have fled their homes and more than a third of the country is outside government control.
