Gareth Southgate’s side have shaken off a slow start to the tournament to reach a second Euros final in as many attempts.
England lost on penalties to Italy at Wembley three years ago but 22-year-old Palmer, who is playing in his first senior tournament, is looking to emulate the Under-21s, who beat Spain in last July’s final to win their age-group European Championship.
“In the first few games, we didn’t play the best that we could and everyone knew that,” added Palmer.
“But now I think as the tournament’s gone on, especially yesterday, I think we had our best game in the tournament, and that’s what you want going into the later stages.
“It’s huge. We played them last year in the Under-21s final, England versus Spain. Even that was a massive game, so I can’t imagine this one.”
Southgate has used Palmer as a substitute in all four of his appearances in Germany this summer, but the Chelsea midfielder has praised the manager for the environment he has created.
“I just think the togetherness that all the players have, he’s created that,” he added.
“It’s our first tournament and we can see how close the lads are and stuff like that. The amount of time he puts into the lads to make us better and for the matches.”