A spoiler and wing of an aircraft. A bottom surface of the spoiler has several longitudinal, elongated grooves. At least some of the grooves are equipped with one or more vortex generators. Further, the invention relates to a wing having in its back part at least one flap and having at least one spoiler of the invention arranged on the section between the wing and flap. The invention also relates to a method and control surface for generating vortexes.