  To a function with values in the power set of a pre--ordered, separated
locally convex space 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. The concept of conjugation is connected to the notion of
$(*,s)$--dualities and duality results are provided.
