The apparatus of this invention is utilized for mounting a wind turbine on the upper end of a wind turbine tower (12), the invention also relates to the method of erecting the same. The tower is provided with a pair of spaced-apart guide rails (26) positioned at one side thereof which extend from the lower end to the upper end of the tower. A carriage (32) is movably mounted on the guide rails and has a platform (52) pivotally mounted thereon adapted to support the wind turbine thereon. The carriage positions the wind turbine so that the spinner/hub and rotor blades may be secured thereto while the wind turbine is at the lower end of the tower and provides a means for slidably moving the wind turbine from the carriage to the upper end of the tower when the carriage has been winched to the upper end of the tower.