In a gas scrubber, a gas stream containing at least one sublimed substance is brought in contact with a liquid or melt stream containing at least one thermally convertible substance, which has a lower temperature than the gas stream. For the intensive and intimate mixing of the gas stream with the liquid or melt stream, an orifice plate with a plurality of holes each surrounded by a retaining edge is provided in the upper part of the gas scrubber, and above the orifice plate inlets for the gas stream and the liquid or melt stream are provided.