AP
He'll stay on the board of directors, and he's going to be a technology advisor.
From the release:
Microsoft also announced that Bill Gates, previously Chairman of the Board of Directors, will assume a new role on the Board as Founder and Technology Advisor, and will devote more time to the company, supporting Nadella in shaping technology and product direction.
Gates has not worked at Microsoft since 2008, when he stepped away to focus on his foundation.
John Thompson, who led the search for a new CEO, will become the chairman.