Disclosed is a device for the inspection or maintenance of devices, for example rotor blades of wind power plants. A frame structure can encompass the device, e.g. a rotor blade, and be used for the inspection or examination or cleaning of the rotor blade or other object. The frame structure has, for example, an inner opening which encloses the object during use. Propellers allow a horizontal movement of the frame structure and thus, for example, of a robot for examining the object. A vertical movement of the robot can be controlled by a cable suspension so that the vertical position of the examination device can be changed. A detection, cleaning, or monitoring system can be provided on the frame structure for detecting the condition of the object, cleaning, monitoring or treatment. A control station can be provided on the ground or on a transporter or other device.