Dutchman Van der Sar, 37, has signed a one-year contract extension.
"Edwin has signed a new contract for another year totally as a player," said United boss Sir Alex Ferguson. "We are pleased with that. His consistency and experience has been a great help to this club."
Despite celebrating his 37th birthday in October, Van der Sar has ended all previous talk about United's goalkeeping problems and will lead his country at Euro 2008 next summer.
However, Ferguson has refused to confirm whether Van der Sar will start next season as his first-choice keeper given England international Ben Foster is also expected to be fit after cruciate knee ligament surgery.
"Edwin is number one at the moment, so he has a chance of being number one next season," said the United boss.
"But you cannot guarantee players' positions and tell them they are going to be in the team.
"Edwin will want to be number one but Ben Foster will be back and I am sure he will want to be number one too. That is great competition."