In a 6-1 decision, the court said it won't hear an appeal from the Capital Area District Library in Ingham County. The library banned weapons at its branches, but the state appeals court last year struck down that policy.
The appeals court said the library was stepping on the authority of the Michigan Legislature by trying to regulate guns.
A controversy began in 2010 when members of a group called Michigan Open Carry occasionally carried guns into a Capital Area library branch in downtown Lansing.
Supreme Court Justice Michael Cavanagh was the only justice who wanted to accept an appeal from the library.