Abstract
We are considering functions with values in the power set of a pre--ordered, separated locally convex space with closed convex images. To each such function, a family of scalarizations is given which completely characterizes the original function. A concept of a Legendre--Fenchel conjugate for set--valued functions is introduced and identified with the conjugates of the scalarizations. To the set--valued conjugate, a full calculus is provided, including a biconjugation theorem, a chain rule and weak and strong duality results of Fenchel-Rockafellar type.