Manager John Sheridan hailed his team's "great achievement" after Chesterfield beat Oldham 1-0 to earn themselves a Wembley final.
The Spireites overcame the Latics in the Johnstone's Paint Trophy Northern final second leg on Monday night.
Already 2-1 up from the first leg, Sheridan's side withstood a barrage of pressure against their League One rivals before clinching victory with a late goal from veteran striker Jack Lester.
The Spireites will now meet either Swindon or Barnet, who complete their southern area final on February 7, at Wembley at the end of March.
"It's brilliant for everyone involved with the club," said Sheridan. "Obviously we'll be trying to win the final, but I've told the lads to enjoy the occasion because getting to any Wembley final is a great achievement.
"We worked our socks off against a very good Oldham side who we knew would create chances. They put us under pressure, but we defended, blocked shots and were always dangerous on the break.
"I'm really proud of all the players because our league form has improved after a poor run and we've carried that into the cups. Our league position still isn't good, but over the last seven or eight games the lads have been showing character and belief."