The invention relates to a liquid/gas state separating device capable of separating the molecules of vapour (V) of a liquid evaporating under the effect of a partial vacuum (31) maintained by pumping means from drops (L) of said liquid carried along by the flow of vapour (V), characterised in that it comprises a vapour deflector (50) and a drop collector (60), the vapour deflector (50) imposing at least one sudden change of direction on the flow of vapour (V).