  The $C^*$-algebra associated with the twisted CCR constructed by W. Pusz and
S.L. Woronowicz is considered. It is proved that the $C^*$-algebras
corresponding to different values of parameter $0<=\mu<1$ are isomorphic. It is
proved that Fock representation is faithful on both *-algebra and $C^*$-algebra
levels.

Operator Algebras;Representation Theory