  We study N=2 supersymmetric U(1) gauge theory in the noncommutative harmonic
superspace with nonanticommutative fermionic coordinates. We examine the gauge
transformation which preserves the Wess-Zumino gauge by harmonic expansions of
component fields. The gauge transformation is shown to depend on the
deformation parameters and the anti-holomorphic scalar field. We compute the
action explicitly up to the third order in component fields and discuss the
field redefinitions so that the component fields transform canonically.
