Wayne County Chief Judge Mary Beth Kelly says she has had enough.
The Detroit News and the Detroit Free Press report she will step down in January.
Kelly has come under fire for acting too independently and trying to privatize the Friend of the Court.
She says a loss of support from her colleagues and anonymous threats influenced her decision to leave.
Governor John Engler appointed Kelly to the court in 1999. The Michigan Supreme Court appointed her chief judge in 2001, 2003 and 2005.
Michigan Supreme Court Chief Justice Clifford Taylor says he's disappointed by Kelly's decision. He calls her one of the most effective chief judges in Michigan's history.