Abstract: The invention concerns a wind turbine comprising a vertical tower with a yaw bearing, a nacelle on top of the yaw bearing, a hub with blades rotatable around a more or less horizontal rotation axis. The nacelle has a generator and a control room, whereby the generator comprises a rotor with a rotor shaft supported on two rotor bearings carrying the hub, and a stator comprising a cylindrical outer shell with a stator diameter that is approximately equal to the diameter of the nacelle and which outer shell has at its ends a front cover plate and a back cover plate each with a rotor bearing for supporting the rotor shaft. In accordance with the invention the rotor shaft is hollow and the hollow hub is accessible from the control room through the hollow rotor shaft.