The invention relates to an unmanned aerial device for performing a resistance, current and/or voltage measurement at an object, in particular a lightning protection measurement at a wind turbine, comprising a contact element with an electrically conductive contact area, which can be brought into contact with a surface of the object, in particular with a lightning protection receptor of a rotor blade, of a nacelle or of a tower of a wind turbine, and comprising an electrically conductive measurement cable, which, with a first end, is connected in an electrically conductive manner to the contact area, and, with a second end, can be connected to a resistance, current and/or voltage measuring device and/or a grounding contact of the object.