The invention relates to a jet adjuster (80) comprising a jet decomposition device (9) and a jet adjustment device (1) located at a distance downstream in the direction of flow, forming the tail end of the jet adjuster (80) on the outflow side with a plurality of through openings (3). The inventive jet adjuster (80) is characterized by the fact that the jet adjustment device (1) has a perforated plate (2) on the outflow side comprising several through openings (3) at least partially in the area embodied as a field of perforations on the plane perpendicular to the direction of flow. Guiding walls (4) separating adjacent through openings from each other extend approximately in the direction of flow and have a wall thickness amounting to a fraction of the inner diameter of a through opening (3) bounded by guiding walls (4) so that the ratio h/D between the height (h) of guiding walls (4) and total diameter (D) of jet adjustment device is less than 1. Inventive jet adjuster is characterized by a particularly good jet formation and a high degree of functional reliability. It is also relatively easy to produce.