La Roja won the 2010 World Cup, but disappointed in Brazil four years later as they failed to make it through the group stage of the tournament.
Julen Lopetegui's side are among the teams fancied to battle for the crown in Russia, and Manchester United stopper De Gea has revealed that his nation are "really excited" for the challenge that awaits them.
"We are in great shape. We've got a great squad and we are going there with a lot of hope and desire and we are really excited about what's ahead," De Gea told Sky Sports News.
"We've got a strong squad and there's a lot of ambition there. We had a great qualifying campaign, but now it's the nice bit, the final stages of the tournament. We've got to go there and try and play our own style of football, try and get victories in the group stage and then go game-by-game.
"It will be an unforgettable experience and I'm sure everyone in the squad will be giving 100% to try and win the World Cup one more time for Spain."
Spain will open their World Cup campaign against Portugal on June 15.