A wind turbine blade (10, 610) for a rotor of a wind turbine having a substantially horizontal rotor shaft, said rotor comprising a hub, from which the wind turbine blade (10, 610) extends substantially in a radial direction when mounted to the hub, the wind turbine blade (10, 610) having a longitudinal direction (r) with a tip end and a root end and a transverse direction, the wind turbine blade further comprising: - a profiled contour (40, 42, 50) including a pressure side and a suction side, as well as a leading edge and a trailing edge with a chord having a chord length extending there between, the profiled contour, when being impacted by an incident airflow, generating a lift, wherein - a surface mounted device (70, 70', 170, 270, 370, 470, 570, 670, 770) is attached to a surface of the wind turbine blade, wherein - the surface mounted device (70, 70', 170, 270, 370, 470, 570, 670, 770) is attached to the surface of the wind turbine blade (10, 610) via at least a first attachment part (77, 77'), which is connected to a part of the surface mounted device (70, 70', 170, 270, 370, 470, 570, 670, 770), wherein - the attachment part (77, 77') comprises a flexible housing (80, 80', 680, 780) that forms a cavity (81, 81', 681, 781) between at least the housing (80, 80', 680, 780) and the surface of the wind turbine blade (10, 610), and wherein - the cavity (80, 80', 680, 780) is filled with an adhesive that provides an adhesive bonding to the surface of the wind turbine blade (10, 610), and characterized in that - the flexible housing is made of a first material and the surface mounted device made of a second material, wherein a hardness of the first material is smaller than the hardness of the second material. - a profiled contour (40, 42, 50) including a pressure side and a suction side, as well as a leading edge and a trailing edge with a chord having a chord length extending there between, the profiled contour, when being impacted by an incident airflow, generating a lift, wherein - a surface mounted device (70, 70', 170, 270, 370, 470, 570, 670, 770) is attached to a surface of the wind turbine blade, wherein - the surface mounted device (70, 70', 170, 270, 370, 470, 570, 670, 770) is attached to the surface of the wind turbine blade (10, 610) via at least a first attachment part (77, 77'), which is connected to a part of the surface mounted device (70, 70', 170, 270, 370, 470, 570, 670, 770), wherein - the attachment part (77, 77') comprises a flexible housing (80, 80', 680, 780) that forms a cavity (81, 81', 681, 781) between at least the housing (80, 80', 680, 780) and the surface of the wind turbine blade (10, 610), and wherein - the cavity (80, 80', 680, 780) is filled with an adhesive that provides an adhesive bonding to the surface of the wind turbine blade (10, 610), and characterized in that - the flexible housing is made of a first material and the surface mounted device made of a second material, wherein a hardness of the first material is smaller than the hardness of the second material. - the attachment part (77, 77') comprises a flexible housing (80, 80', 680, 780) that forms a cavity (81, 81', 681, 781) between at least the housing (80, 80', 680, 780) and the surface of the wind turbine blade (10, 610), and wherein - the cavity (80, 80', 680, 780) is filled with an adhesive that provides an adhesive bonding to the surface of the wind turbine blade (10, 610), and characterized in that - the flexible housing is made of a first material and the surface mounted device made of a second material, wherein a hardness of the first material is smaller than the hardness of the second material.