A device for generating an atmospheric plasma beam for treating the surface of a workpiece includes a tubular housing with an axis, an inner electrode within the housing, and a nozzle assembly with a nozzle opening for discharging a plasma beam to be generated in the housing. The direction of the nozzle opening runs at an angle relative to the axis, and the nozzle assembly can be rotated about the axis. By the aforementioned device, disadvantages are at least partly eliminated and uniform treatment of the surface is achieved in that a shield surrounds the nozzle assembly, and the shield is designed to change the intensity of the interaction of the plasma beam to be generated with the surface of the workpiece depending on the rotational angle of the nozzle assembly relative to the axis. Also provided are a system and method for treating the surface of a workpiece.