  In this paper we will analyse the Aharony-Bergman-Jafferis-Maldacena (ABJM)
theory in $\mathcal{N}=1$ superspace formalism. We then study the quantum gauge
transformations for this ABJM theory in gaugeon formalism. We will also analyse
the extended BRST symmetry for this ABJM theory in gaugeon formalism and show
that these BRST transformations for this theory are nilpotent and this in turn
leads to the unitary evolution of the $\mathcal{S}$-matrix.
