Stability of the GIANO spectrograph. The dispersion solution of the spectra taken at A and B position differs as a function of the spectral order considered (left panel, averaged over the observing night). In addition, we measure temporal variations in the global dispersion solution (right panel). Their amplitude differs between the first and the second night of observations (top-right and bottom-right panels, respectively). These measurements suggest that although A and B spectra move coherently (i.e. their relative shift stays the same), their absolute position is variable on a timescale of minutes. Furthermore, the overall stability of GIANO differs between observing nights.