[en] Possibilities to measure W-boron magnetic moment before these particles are really produced, have been considered. For this purpose the cross section for the process e+e- → γνsub(i)anti νsub(i) (where i=e, μ, tay,...) has been calculated with an account for the diagram (3W) which contains W-boson gyromagnetic ratio gsub(W). The results obtained are valid for not very high energies, since the calculations have been made only in the first order of (s/2Msub(W)sup(2))