Goals from Mikel Oyarzabal, converted from the penalty spot, and Pedro Porro sent Spain through at AT&T Stadium in Arlington, Texas, with France unable to find a way past a well-organised Roja defence.
Speaking to L'Equipe after the match, De la Fuente reflected on his side's growing confidence through the tournament.
"I'm still surprised by what my team manages to do. We keep improving, from one match to the next, from one competition to the next. That improvement never stops. It's something very special to show these values. It doesn't happen by chance, but through effort, talent and sacrifice.
"We had planned to reach this stage of the competition in the best possible shape. The players are hugely excited, very happy with our level of football. We've reached a high point."
Asked how Spain had managed to shut down a dangerous French attack, the coach pointed to preparation and discipline rather than individual battles.
"In the build-up to the match, a number of journalists reminded me that we were going to face one of the best teams in the world. Well, France were thinking the same about us. That was the best way to nullify the opposition: effort, discipline, organisation. We read the phases of play well, that's what we do best. Spanish players know how to read the game, that's the result of our work in the academies, of all the coaches in Spain. Even though we're happy, we want more, we want to bring this World Cup home, that would be something wonderful."
Didier Deschamps had questioned the standard of officiating after the defeat, but De la Fuente was reluctant to engage with the criticism.
"When things don't go your way, you can always look for an excuse. We've also had difficult moments with referees. As for what Didier Deschamps said, I don't think that's the case. There were a few very correct offside calls, a few fouls here and there, but I'm not here to talk about the officiating, what I want is for us to keep improving."
On the tactical plan that nullified France, De la Fuente credited his players for executing a high-pressing approach.
"We had to manage to press high, to be right behind them. We know the French side well. The players interpreted the instructions very well. This team is so committed, the message was that we were going to face one of the best sides but that we would have the best team."
Spain now await their final opponents as they bid to add a second World Cup to the one won in 2010.