Device for carrying out a method for producing an item according to the method of selective powder melting by layer-by-layer building up of material in powder form, comprising: - an installation space which is configured to accommodate the item to be produced; - a powder delivery apparatus which is equipped with a powder reservoir (122; 212) and which is configured to supply material powder into the installation space; - a powder layer preparation apparatus which is configured to prepare consecutive layers of the supplied material powder on a carrier arranged in the installation space; - an irradiation apparatus which is configured to irradiate an ultimately prepared powder layer and as a result locally fuse it; and - a shielding gas circulation device which is configured to circulate a shielding gas present in the installation space; wherein the device furthermore comprises at least one conditioning apparatus which is configured, in a conditioning mode, to condition the shielding gas circulated by the shielding gas circulation device in terms of its temperature and/or its humidity, characterised in that the conditioning apparatus comprises a countercurrent heat exchanger for pre-cooling of the shielding gas, to which a cooling circuit is assigned coupled via a cooling unit, in which cooling circuit a heated coolant is compressed and heated initially by a compressor, subsequently cooled and liquefied by a cooler and then the cooled coolant is decompressed by a throttle, wherein the cooled coolant acts on the pre-cooled shielding gas flow and moisture present therein condenses in the area of the cooling unit, wherein a condensate discharge system for removing this condensed moisture from the conditioning apparatus is furthermore provided. - an installation space which is configured to accommodate the item to be produced; - a powder delivery apparatus which is equipped with a powder reservoir (122; 212) and which is configured to supply material powder into the installation space; - a powder layer preparation apparatus which is configured to prepare consecutive layers of the supplied material powder on a carrier arranged in the installation space; - an irradiation apparatus which is configured to irradiate an ultimately prepared powder layer and as a result locally fuse it; and - a shielding gas circulation device which is configured to circulate a shielding gas present in the installation space; wherein the device furthermore comprises at least one conditioning apparatus which is configured, in a conditioning mode, to condition the shielding gas circulated by the shielding gas circulation device in terms of its temperature and/or its humidity, characterised in that the conditioning apparatus comprises a countercurrent heat exchanger for pre-cooling of the shielding gas, to which a cooling circuit is assigned coupled via a cooling unit, in which cooling circuit a heated coolant is compressed and heated initially by a compressor, subsequently cooled and liquefied by a cooler and then the cooled coolant is decompressed by a throttle, wherein the cooled coolant acts on the pre-cooled shielding gas flow and moisture present therein condenses in the area of the cooling unit, wherein a condensate discharge system for removing this condensed moisture from the conditioning apparatus is furthermore provided.