  A possibility of a verification of CPT-invariance of QED for bound states by
example of muonium or antimuonium produced in reactions of scattering of
electrons or positrons by nuclei is considered. The number of events of the
muonium production is estimated for contemporary accelerators. The method of
the detection of muonium by measuring of oscillations of the decay curve caused
by the interference between the ground and excited state of muonium is
suggested. The admixture of the excited muonium to the final state is
calculated.
