Chesterfield have parted company with Lee Richardson after deciding not to renew his contract.
He had been in charge at Saltergate since March 2007 when he replaced Roy McFarland after working as assistant manager for five years.
Chairman Barrie Hubbard said: "Lee's had two full seasons as manager in which the club has come close to getting promotion, but we feel the time is now right to make a change.
"We thank Lee for all his efforts and wish him and his family all the best for the future."
Richardson added: "I want to thank my staff and the players of the last two seasons for all their efforts.
"I also wish to thank chairman Barrie Hubbard and the board of directors for giving me the opportunity to manager Chesterfield FC. I recognise it's time for us all to have a change.
"In thanking the fans of Chesterfield FC for their support, I'd also like to wish everyone involved at the club the very best for the future."
The Spireites finished tenth in the season just ended.