A device for producing three-dimensional workpieces , comprising: - a carrier for receiving raw material powder , - a build chamber wall which extends substantially vertically and which is adapted to laterally delimit and support the raw material powder applied to the carrier , - an irradiation unit for selectively irradiating the raw material powder applied to the carrier with electromagnetic radiation or particle radiation in order to produce on the carrier a workpiece manufactured from the raw material powder by an additive layer building method, wherein the irradiation unit comprises at least one optical element, and - a vertical movement device which is adapted to move the irradiation unit vertically with respect to the carrier , wherein the build chamber wall and the carrier are adapted to be connected to one another in a stationary manner during the vertical movement of the irradiation unit so that the vertical movement takes place relative to the carrier and relative to the build chamber wall , wherein the build chamber wall is rigidly connected to the carrier and/or to a base of the device, or wherein the build chamber wall is detachably connected to the carrier and/or to the base and is adapted to be detached from the carrier on completion of a build process, in order to remove the finished workpiece , wherein the device further comprises a horizontal movement device which is adapted to move the irradiation unit horizontally with respect to the carrier and with respect to the raw material powder applied to the carrier , wherein the device comprises a plurality of build chambers arranged side by side, each of which has a build chamber wall which laterally surrounds the respective build chamber , and a carrier , and wherein the horizontal movement device is adapted to move the irradiation unit from a first build chamber of the plurality of build chambers to a second build chamber of the plurality of build chambers. - a carrier for receiving raw material powder , - a build chamber wall which extends substantially vertically and which is adapted to laterally delimit and support the raw material powder applied to the carrier , - an irradiation unit for selectively irradiating the raw material powder applied to the carrier with electromagnetic radiation or particle radiation in order to produce on the carrier a workpiece manufactured from the raw material powder by an additive layer building method, wherein the irradiation unit comprises at least one optical element, and - a vertical movement device which is adapted to move the irradiation unit vertically with respect to the carrier , wherein the build chamber wall and the carrier are adapted to be connected to one another in a stationary manner during the vertical movement of the irradiation unit so that the vertical movement takes place relative to the carrier and relative to the build chamber wall , wherein the build chamber wall is rigidly connected to the carrier and/or to a base of the device, or wherein the build chamber wall is detachably connected to the carrier and/or to the base and is adapted to be detached from the carrier on completion of a build process, in order to remove the finished workpiece , wherein the device further comprises a horizontal movement device which is adapted to move the irradiation unit horizontally with respect to the carrier and with respect to the raw material powder applied to the carrier , wherein the device comprises a plurality of build chambers arranged side by side, each of which has a build chamber wall which laterally surrounds the respective build chamber , and a carrier , and wherein the horizontal movement device is adapted to move the irradiation unit from a first build chamber of the plurality of build chambers to a second build chamber of the plurality of build chambers. <EOS>