Chung retired with severe blisters trailing 6-1 5-2, meaning Federer remains on course to land his sixth Australian Open title and the 20th Grand Slam of his career.
Federer, 36, took the first set and carved out three break points at 0-40 in the third game of the second.
The 21-year-old Chung was the first Korean to reach the semifinals at a major and had taken out Djokovic and No. 4-ranked Alexander Zverev on his way to the last four.
Tennis - Australian Open - Semifinals - Rod Laver Arena, Melbourne, Australia, January 26, 2018.
But that incensed the 19-time Grand Slam champion who proceeded to launch into an unusual angry outburst.
Nineteen-time grand slam victor Federer will play Marin Cilic in a showdown on Sunday, yet he was left with mixed feelings after reaching his 30th major final.
However, the Croatian has powered his way into the decider and looked particularly impressive in his quarter-final against Rafael Nadal before the Spaniard had to retire through injury.
Federer will meet Cilic in Sunday's final in a repeat of last summer's Wimbledon final - when coincidentally Cilic was in tears because of blisters.
"We'll see a fresh and ready Marin this time around".
"I think I did right thing", Chung said in his post-match news conference.
Survey suggests loot boxes are here to stay
That's up from 3% in 2017 and there were even more positive results noted from among developers looking to the future. Almost 4,000 polled developers say that have an interest in the Switch.
Nicknamed "The Professor" due to his trademark thick white-rimmed glasses, Chung said he retired because his blisters were "red raw". They tried injections to see if it numbed the pain, it didn't work. But I played a good match. "It was more for the [spectators] than for me", he joked in his on-court interview after the match.
"I'm just trying to play (like) Novak because he playing good in baseline and he's mentally really strong", Chung said after beating Djokovic in the fourth round. "And I hope I can read his serve".
"It's worse than regular blisters. I can play, like, more comfortable on the court with the great players like Roger".
"I'm happy to be able to make semis in grand slam".
He remembers his sole loss to Cilic all too well, a straight-sets defeat at the 2014 U.S. Open.
He hasn't dropped a set in the first six matches of his defense and is quietly confident.
Cilic went on to win the US title - his only Grand Slam trophy.
'I'm excited to play against him, he's a great guy, we won the Laver Cup together and had a blast.
Many ticket holders will be in ecstasy at the prospect of watching Roger Federer, arguably the world's most popular athlete, in his 30th grand slam final.
"However, I had to make a tough decision given that I can not compete 100% against Roger, in front of many tennis fans". "Please understand. I wish all the best luck for @rogerfederer in the finals". I (am) going to play on the court.