A lifting device for lifting a rotor of a wind turbine, where the lifting device comprises: - at least one base unit having one or more mounting means configured for mounting to matching mounting means located on an outer surface of a hub of the rotor, the hub further having at least two mounting interfaces (11, 12) configured for mounting to at least two wind turbine blades; - at least one turning unit comprising a trolley assembly configured to move along a track located on the base unit, wherein a gear coupling (32,33) is arranged on the trolley assembly and configured to move the trolley assembly along the track so that the rotor is turned in an angle of substantially 90 degrees from a lifting position into an installation position; - at least one lifting element (20,20') located on the trolley assembly configured to be connected to an external lifting unit; - a control unit configured to control the operation of the lifting device, characterised in that the lifting device further comprises a drive train comprising the gear coupling (32,33) having a pinion gear engaging a matching gear rim located on the track wherein the pinion gear is connected to a motor driven by a power unit, that the turning unit comprises a braking mechanism configured to stop the rotor in any intermediate position between the lifting position and the installation position, that the braking mechanism is chosen between an electrical, hydraulic, pneumatic, or electromagnetic brake and said braking mechanism is arranged relative to the drive train for applying a braking force to the trolley assembly, that the braking mechanism locks the trolley assembly and thus the rotor in any position along the track when activated, and that said braking mechanism is released when the control unit is activated. - at least one base unit having one or more mounting means configured for mounting to matching mounting means located on an outer surface of a hub of the rotor, the hub further having at least two mounting interfaces (11, 12) configured for mounting to at least two wind turbine blades; - at least one turning unit comprising a trolley assembly configured to move along a track located on the base unit, wherein a gear coupling (32,33) is arranged on the trolley assembly and configured to move the trolley assembly along the track so that the rotor is turned in an angle of substantially 90 degrees from a lifting position into an installation position; - at least one lifting element (20,20') located on the trolley assembly configured to be connected to an external lifting unit; - a control unit configured to control the operation of the lifting device, characterised in that the lifting device further comprises a drive train comprising the gear coupling (32,33) having a pinion gear engaging a matching gear rim located on the track wherein the pinion gear is connected to a motor driven by a power unit, that the turning unit comprises a braking mechanism configured to stop the rotor in any intermediate position between the lifting position and the installation position, that the braking mechanism is chosen between an electrical, hydraulic, pneumatic, or electromagnetic brake and said braking mechanism is arranged relative to the drive train for applying a braking force to the trolley assembly, that the braking mechanism locks the trolley assembly and thus the rotor in any position along the track when activated, and that said braking mechanism is released when the control unit is activated.