A device for producing three-dimensional workpieces, comprising: - a carrier for receiving raw material powder, - a build chamber wall (11, 11a, 11b) 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 (11, 11a, 11b) 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 (11, 11a, 11b), wherein the build chamber wall (11, 11a, 11b) is rigidly connected to the carrier and/or to a base of the device, or wherein the build chamber wall (11, 11a, 11b) 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 (13a, 13b) arranged side by side, each of which has a build chamber wall (11a, 11b) which laterally surrounds the respective build chamber (13a, 13b), 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 (11, 11a, 11b) 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 (11, 11a, 11b) 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 (11, 11a, 11b), wherein the build chamber wall (11, 11a, 11b) is rigidly connected to the carrier and/or to a base of the device, or wherein the build chamber wall (11, 11a, 11b) 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 (13a, 13b) arranged side by side, each of which has a build chamber wall (11a, 11b) which laterally surrounds the respective build chamber (13a, 13b), 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.