It has been proved theoretically that the combined process of desorption and evaporation can take place both in stable and unstable regimes. The conditions of hydrodynamic instability of the process have been determined. It has been shown that carbon dioxide desorption From water combined with its evaporation into dry nitrogen takes place in a hydrodynamically unstable regime. Numerical solution of the spectral problem of this process for small perturbations has been performed. The time during which the process passes into an unstable regime has been estimated.