NOVELTY - The element (1) has a sandwich structure with a cover layer (3), which partially surrounds a closed-cell foam core (2) and is formed from carbon fibers. The core comprises an integrated reinforcement (27) for portion-wise variation of rigidity. The integrated reinforcement is coupled together with mutually opposing cover sheets (25, 26) of the cover layer, where the integrated reinforcement and the cover layer are formed monolithically. The integrated reinforcement has a reinforcement pin that is arranged at an inclination angle and in an inclination direction to the cover sheets.    USE - Structural element for use as a tail unit surface, an aerodynamic effective surface and a fuselage element of an aircraft and a spacecraft, and for a rotor blade of a wind turbine (all claimed). Can also be used during a vehicle construction or shipbuilding.    ADVANTAGE - The core comprises the integrated reinforcement for portion-wise variation of rigidity, so that aero-elastic characteristics of the structural element can be optimized. The integrated reinforcement and the cover layer are formed monolithically, so that an optimum transmission of force from the reinforcement to the cover layer and vice versa can be allowed. The integrated reinforcement is provided with the reinforcement pin that is arranged at the inclination angle and in the inclination direction to the cover sheets, so that rigidity of the core can be adjusted in a flexible manner, thus simplifying manufacturing of the structural element. The foam core is made of the plastics material such as polymethacrylimide, so that the structural element is manufactured in a light-weight manner, thus reducing fuel consumption.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for manufacturing a structural element.    DESCRIPTION OF DRAWING(S) - The drawing shows a partial sectional view of a structural element.    Structural element (1)    Closed-cell foam core (2)    Cover layer (3)    Cover sheets (25, 26)    Integrated reinforcement (27)