A device for monitoring objects, in particular for monitoring industrial environments, such as paper mills and manufacturing and/or finishing processes of a paper, board or other fibrous web being carried out therein, includes a monitoring camera, the camera with its objective being arranged in a rotationally symmetrical protective housing rotating about an axis of rotation, and a protective housing to be mounted at its one end on a rigid hollow shaft and, at its coaxially opposite other end, to have a co-rotating blower pipe or merge into the latter, and for compressed air to be applied to the protective housing, including the blower pipe.