The Science ministry is a Nod department devoted to research and development. It's Ministers worked with Kane to develop the liquid tiberium bomb during the Third Tiberium War. Its Science Minister was a member of Kane's Inner Circle.
The ministry was headquartered in a building in Sarajevo. During the Battle at Temple Prime, the headquarters was captured by GDI forces. However, it was destroyed in the aftermath of the liquid tiberium detonation. It's assumed that major science ministry and personnel were evacuated before the battle.