Federer was outplayed for a large part of the match but lifted when it mattered to beat the eighth seeded Chardy in three sets 6-3, 6-7 (3/7), 6-3.
The one hour, 55 minute win puts Federer into Sunday’s final against local hero Lleyton Hewitt, who took beat Japan’s second seeded Kei Nishikori 5-7, 6-4, 6-3.
Federer, who at 32 is the same age as Hewitt, admitted he found it difficult to beat the Aussie at the start of their careers.
Federer said: “We go back 17 years, our coaches back then were best friends. It’s out first chance to play in Australia. I struggled a lot against him early in my career.”