A device for mixing fuel and air of a jet engine includes at least one air-carrying duct and at least one further fuel-carrying duct. Guide elements extending over the duct height and distributed over the circumference of the duct are provided at least in the air-carrying duct, in the area of which guide elements a twist can be imparted to the air flowing in the air-carrying duct in order to improve mixing between the air and the fuel downstream of the ducts. The guide elements are provided at a trailing edge with at least one downstream extending projection and/or upstream extending recess designed at least approximately or at least in some areas with a sharp edge.