Abstract: In order to provide an attachment element for fastening of attachment parts (P) to a metal inner tower wall (T) of a tower of a wind energy system, comprising a first end side for welding to the inner tower wall (T) and a second end side for fastening an attachment part (P), said second side opposite the first end side, wherein the resultant weld connection between said attachment element and the tower wall is under a reduced stress, thereby enabling the connection point to be assigned to a higher fatigue class, it is proposed that such an attachment part have a total cross-sectional material thickness that is reduced near the first end side in comparison to a total material thickness in a cross-section shifted toward the second end side.