A process is provided for producing a rotor which is made by welding together disk-shaped and/or drum-shaped elements, in particular disks, wherein a device is used to join the disks together axially in sequence along a longitudinal axis and the disks are welded in a two-stage welding process. As they are joined together, the disks are stacked axially in the vertical direction. A first welding process takes place in a vertical orientation of the stacked disks, followed by a second welding process in a horizontal orientation of the stacked disks.