In an apparatus for monitoring and securing danger zones on power-driven textile machines, in particular spinning room preparatory machines, having movable machine parts, an optical monitoring device monitors a movable danger zone to form a movable protection zone, such that a person and/or an object intruding into the danger zone triggers a switching operation. To produce an apparatus that allows guarding of danger zones in a simple and reliable manner, stationary monitoring device is present, which is selectively activatable and forms a dynamically movable protection zone around the movable danger zone.