The present invention provides a horizontal axis wind turbine comprising a tower, a nacelle mounted on top of the tower, and a rotor rotationally mounted to the nacelle. The rotor comprises a hub carrying a plurality of blades. Furthermore, the rotor comprises a spinner covering the hub and defining a space between the spinner and the hub. The spinner and hub are sized such that the space allows service personnel to work within the space. A service floor for supporting the service personnel is provided in the space. The service floor provides a substantially plane support structure.