Van der Sar to quit as Ajax chief after 'tough period'
Van der Sar's resignation comes on the back of the worst season in 14 years for the top Dutch club which finished third in the Eredivisie after a 3-1 drubbing by FC Twente on Sunday.
"After almost 11 years on the board, I am done," Van der Sar, 52, said in a statement.
"We have experienced wonderful things together, but it has also been an incredibly tough period," the former Manchester United 'keeper said, who retired from professional football in 2011.
Ajax have failed to qualify for the Champions League after finishing third in the Eredivisie behind Feyenoord and PSV Eindhoven.
Media reports including the NOS public broadcaster and daily tabloid De Telegraaf said supporters held Van der Sar responsible for the club's drop in success, following the departure of sporting director Marc Overmars and trainer Erik ten Hag.
Former Dutch international Overmars quit after admitting to sending inappropriate messages to female staff at Ajax, while the successful Ten Hag left for Manchester United in April last year.
Van der Sar said he needed to "take some distance, to get some rest, and to do other things".
Ajax supervisory board chairman Pier Eringa said the club "wanted Edwin to stay, but he had made his decision. We have to respect that".
Van der Sar's contract ran until June 30th, 2025.
"The last season does not reflect the entire period that he has been in charge of Ajax," Eringa stressed.
Regarded as one of the world's all-time best goalkeepers, Van der Sar played for Ajax from 1990-1999, winning the Champions League in 1995.
He went on to lift the European Cup again in 2008 with Manchester United after spells at Juventus and Fulham.
Van der Sar returned to Ajax in 2012 as director of marketing before being promoted four years later to CEO.
He is also the second-highest-capped Netherlands player of all time with 130 international appearances.