The third seeded Briton had spent just over seven hours on court in his previous four matches and only needed another 111 minutes to complete a one-sided hammering of the world number 36.
Chardy had won the last meeting between the two in Cincinnati in August but another upset was never on the cards.
Murray broke in the opening game and surged into a 4-0 lead before taking the opening set in 44 minutes.
The Scot then won eight games in a row to race through the second set and open up a 3-0 advantage in the third.
He failed to serve out for the match at 5-1 but the US Open champion wrapped up victory when the Frenchman ballooned a forehand into the sky on Rod Laver Arena.
Murray had carried out his game-plan to perfection and within a couple of hours of finishing his match, he was back out on court, practising under the lights to get a feel for the cooler conditions he will experience on Friday.
Facing him for a spot in the final will be 17-times Grand Slam champion Roger Federer.
Murray's attention to detail and desire to get straight back to work shows the influence of his coach Ivan Lendl.
"I played a couple of matches (in the warm-up event) in Brisbane in the evening but it's slightly different there, as well, because there's a roof," said Murray, who has reached the last four without dropping a set.
"And that's why tonight (Wednesday), rather than going and watching (Federer v Tsonga), I'll go out and hit some balls under the lights to be as best prepared as possible. And I'll do the same tomorrow."
At his news conference, Murray wore a T-shirt with the words "PREPARE, ATTACK, DESTROY" on the front, exactly what Lendl was famous for and exactly what Murray did against Chardy, a Frenchman appearing in his first Grand Slam quarter-final.
"I started the match pretty well, I thought," said Murray.
"Then when he got a break back in the first set, I became a bit tight. He's a tough guy to play against because of the nature of his game and his style.
"He goes for a lot of shots and he can play a couple of games where he misses and then three, four games he's hot and he makes very few errors and puts you under a lot of pressure.
"But I thought I did a pretty good job throughout the match. There were a couple of games I could have done a bit better on, but for the most part it was good."
Chardy's strength is his serve and his forehand but more often than not, Murray made sure that he did not have enough time or space to use them to attack.
"I wanted to make sure that I kept the ball away from the middle of the court," he said. "Then I was able to hit to his backhand and come into the net sometimes."
Murray won 17 of 20 points at the net, an excellent percentage, and also took a little pace of his average first serve to increase the emphasis on placement, varying his second serve well so that Chardy found it more difficult to attack.
"Andy had a response for everything," his unseeded opponent told French reporters. "He will be very hard to beat here."
Having won his first Grand Slam title in New York last September, Murray is trying to become the first man in the professional era to follow up his maiden Grand Slam by immediately winning another.
History may be against him but he admitted that winning the U.S. Open had taken a lot of pressure off his shoulders.
"I feel probably a little bit calmer than usual," he said.
"But I still have an understanding of how difficult it is to win these events. With the players that are still left in the tournament, it's going to be a very tough, tough few days if I want to do that.
"So I'll just stay focused, work hard in my next couple of practice sessions, and hope I can finish the tournament well."
Murray will go into the semi-finals having played all of his matches in the day session but said he was not worried about having to adjust to the cooler, evening conditions or missing out on a showpiece night match until Friday.
"If I was whoever decides the schedule, I also would have put Federer against Tsonga on as the night match tonight because it's the best match of the day," he said.
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