  We propose a new unified formulation of the current algebra theory in terms
of supergeometry. We take a QP-structure, i.e. a differential graded symplectic
structure, on a graded cotangent bundle as a fundamental framework. A Poisson
bracket in a current algebra is constructed by the so called derived bracket of
the graded Poisson structure induced from the above symplectic structure. By
taking a canonical transformation on a QP-manifold, correct anomalous terms in
physical theories are derived. A large class of current algebras with and
without anomalous terms are constructed from this structure. Moreover, a new
class of current algebras related higher structures are obtained
systematically.
