The 31-year-old had recovered two-set deficits in all three of his previous rounds at Roland Garros but Ferrer was rock solid as he thrashed his countryman in one hour 25 minutes.
Ferrer was all over Robredo from the start, producing a near-perfect display to reach the semi-finals for the second successive year.
Ferrer has conceded only 36 games in five rounds.
"Playing with a guy like David, who is a machine, is very tough," Robredo said.
There is a growing feeling that after years of dogged persistence the Valencia native can reach a major final.
With world number two Andy Murray missing, Ferrer was bumped up to fourth seed from his world ranking of five and, luckily for him, he was placed in the other side of the draw to undisputed claycourt king Rafael Nadal.
Even Tsonga's straight-sets win over Federer appears to have loaded the dice in Ferrer's favour as he has a morale-sapping 0-14 career record against Federer but does lead Tsonga.
Ferrer is not one for hyperbole, however, and, despite his hot form, defends himself against overly inflated expectations, just as he does his baseline.
"Today all players reaching this level in a tournament, to me, are at the same level. So I don't want to think about it. I want to make it as far as possible," he said.
He was asked: was it a good draw?
"I don't know. I have to win all my matches. It's difficult," he said.
"But I do realise it's not the first round of a small tournament. It's a semi-final. But I'm not going to start dreaming and celebrate before it's time."
"It's just one more match I have to play in my career."
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