A protective device (10, 110, 210, 310) in the form of a protective door or protective gate for a plant, in particular a production plant, the protective device (10, 110, 210, 310) comprising: - a closing element (26, 126, 226, 326), in particular a high-speed closing element (26, 126, 226, 326), having a closing edge (28, 128, 228, 328), wherein the closing element (26, 126, 226, 326) is movable in a closure plane (18, 118, 218, 318) between an open position and a closed position, - a drive (38, 138) for driving the closing element (26, 126, 226, 326), - a monitoring device (64, 164, 264, 364) with at least one sensor unit (66, 166, 266, 366), which monitors an forefield (72, 172, 272, 372) of the closure plane (18, 118, 218, 318), in order to detect the intrusion of foreign objects (194, 196, 198, 296, 396) into a safety zone (176, 276, 376) in the forefield (72, 172, 272, 372) of the closure plane (18, 118, 218, 318), and - a control device (50, 150) that is configured to selectively operate the drive (38, 138) in a first operating mode or in a second operating mode based on data that is provided by the monitoring device, depending on whether a detected foreign object (194, 196, 198, 296, 396) is located within the safety zone (176, 276, 376) in a first distance range (178, 278, 378) or a second distance range (180, 280, 380), wherein the first operating mode is associated with the first distance range (178, 278, 378) and the second operating mode is associated with the second distance range (180, 280, 380), wherein the first operating mode is a stop and reverse mode, wherein the second operating mode is a reduced speed mode, and wherein the second distance range (178, 278, 378) is in front of the first distance range (180, 280, 380), characterized in that the control device is adapted to define dimensions of the first distance range (178, 278, 378) and the second distance range (180, 280, 380) depending on the current closing speed of the closing element (26, 126, 226, 326). - a closing element (26, 126, 226, 326), in particular a high-speed closing element (26, 126, 226, 326), having a closing edge (28, 128, 228, 328), wherein the closing element (26, 126, 226, 326) is movable in a closure plane (18, 118, 218, 318) between an open position and a closed position, - a drive (38, 138) for driving the closing element (26, 126, 226, 326), - a monitoring device (64, 164, 264, 364) with at least one sensor unit (66, 166, 266, 366), which monitors an forefield (72, 172, 272, 372) of the closure plane (18, 118, 218, 318), in order to detect the intrusion of foreign objects (194, 196, 198, 296, 396) into a safety zone (176, 276, 376) in the forefield (72, 172, 272, 372) of the closure plane (18, 118, 218, 318), and - a control device (50, 150) that is configured to selectively operate the drive (38, 138) in a first operating mode or in a second operating mode based on data that is provided by the monitoring device, depending on whether a detected foreign object (194, 196, 198, 296, 396) is located within the safety zone (176, 276, 376) in a first distance range (178, 278, 378) or a second distance range (180, 280, 380), wherein the first operating mode is associated with the first distance range (178, 278, 378) and the second operating mode is associated with the second distance range (180, 280, 380), wherein the first operating mode is a stop and reverse mode, wherein the second operating mode is a reduced speed mode, and wherein the second distance range (178, 278, 378) is in front of the first distance range (180, 280, 380), characterized in that the control device is adapted to define dimensions of the first distance range (178, 278, 378) and the second distance range (180, 280, 380) depending on the current closing speed of the closing element (26, 126, 226, 326).