The striker, 28, is coming towards the end of his fifth season in England but this will be his first match played at the famous London ground without wearing a Spain jersey.
The Blues forward experienced half an hour at the stadium when he came on as a substitute in the 1-0 defeat to the Three Lions in November and is hoping that the cup clash will bring better memories.
“Wembley has so much history,” Torres told Chelsea's official website. “English teams have a couple of chances every season to play there and it's massive.
“All the players want to play in those games, it's my fifth season in England but this is the first time I'm going there.
“It's very exciting because we have the chance to reach the final in a London derby, so it will be very nice to be there and to play, so I'm looking forward to it.
“I'd never played against England at Wembley before that game [in November]. I'd played against them at Old Trafford, which was nice, but Wembley is so famous.
"All the Spanish supporters were excited and taking pictures, even the players were taking photos in training the night before.
"If you like football, you want to play at Wembley, I had the chance with Spain, but obviously they're not very good memories from that day as we lost, so hopefully on Sunday it will be better."
The former Liverpool and Atletico Madrid man believes that cup competitions are held in higher regard in England than in his native country.
“In Spain, the domestic cup is not as important as the FA Cup is to English teams, it's more of a minor competition," he observed.
“It's nice to see in England that the tradition is still there and the FA Cup is very close to the league in terms of significance.
“All the fans are very excited, the players want to play in the final and it's nice to see the importance which is given to the competition in this country.
“The [League] Cup is a little bit further behind, but it would be fantastic to add the FA Cup to your record.”
The FA Cup final will also be played at Wembley but Torres believes that the fact that the semi-finals are being played at the ground shows how important the cup is considered.
“It gives you an idea of how big the semi-finals are, I think it's going to be massive, a game with great intensity against a great team,” the striker added.
“If the semi-final is that big, obviously the final is even bigger.
“It will be great for the Chelsea fans and players, we have players here who have played at Wembley loads of times, but for some of us it's the first time and so it will be more special for us.”