The 25-year-old swimmer set the second fastest time in the heats in 56.80 seconds, behind American Torri Huske (56.29).
"I felt really relaxed and relaxed," reacted the Frenchwoman, 6th at the Tokyo Olympics last summer.
"Sometimes when I'm relaxed, that's what works best and as soon as I try to put a little aggressiveness, it doesn't necessarily work better (...) It was a good race", a- she added.
The final will take place on Sunday at 6:10 p.m.
During the evening, Florent Manaudou and Maxime Grousset, on the other hand, were eliminated in the semi-finals of the 50m butterfly.
Grousset achieved the ninth time in the semis in 23 sec 10 while Manaudou finished 12th (23.23), insufficient to reach the final.
"I am in my place, I think," said Manaudou, who says he is "in a year of transition".
"I really enjoyed it and I'm doing my best time since 2015, it's not too bad either."
The halves of the event were dominated by the Briton Benjamin Proud, just ahead of the American Caeleb Dressel and the Italian Thomas Ceccon.
© 2022 AFP