The Gunners face the holders at Wembley Stadium on Saturday as they look to take a big step towards their first piece of silverware since 2005.
Szczesny now hopes that he and his teammates can seize the opportunity and return to Wembley for next month's final.
"It's huge - we know that we're in a very strong position to win the FA Cup this year, and we're two games away from doing so," he told the club's official website.
"We're at Wembley so we know how important it is for the fans and all the players. I hope it's going to be a very positive day for the club."
Arsenal head into Saturday's encounter having failed to win their last three games.