A nozzle assembly for generating an atmospheric plasma jet includes an inlet, through which the jet can be introduced into the nozzle assembly, and a channel connected to the inlet so that the plasma jet introduced is conducted through the channel. Multiple nozzle openings are provided in the channel wall along the channel, through which a plasma jet can exit the assembly. The cross section of the channel in the region of a nozzle opening is shaped in such a way that a virtual medial plane runs between a virtual first tangent plane of the cross section through the nozzle opening and a virtual second tangent plane of the cross section opposite thereto and parallel to the first tangent plane divides the cross section into a first cross-sectional area at the nozzle opening. The cross-sectional surface of the first cross-sectional area differs from the cross-sectional surface of the second.