A monitoring device with a light grid for detecting objects in a monitoring area with a transmitter/receiver unit at one edge of the monitoring area and beam deflection means at the opposite edge of the monitoring area, wherein the transmitter/receiver unit has at least one transceiver which is designed to transmit and receive light beams (3a, 3b), the light beams (3a, 3b) striking the beam deflecting means and being guided from there back to the transceiver, and in which a beam of light beams (3a, 3b) is interrupted when an object is engaged in the monitoring area, and with an evaluation unit in which a binary switching signal (23a, 23b) is generated as a function of received signals of the transceiver, the switching states of which indicate whether an object is present in the monitoring area, wherein redundant optical paths formed by light beams (3a, 3b) are formed in the monitoring area with said at least one transceiver, characterised in that said at least one transceiver has a transceiver controller with a transmit controller controlling at least two transmit elements (4a, 4b) and with a receive controller controlling at least two receive elements (5a, 5b), wherein different optical paths are generated with light beams (3a, 3b) emitted by the transmitting elements (4a, 4b), in that said at least one transceiver controls several pairs of receiving elements (5a, 5b) with its transmitting controller and controls several pairs of receiving elements (5a, 5b) with its receiving controller, wherein the light beams (3a, 3b) of the transmitting elements (4a, 4b) form a multibeam arrangement with redundant optical paths, in that the light beams (3a, 3b) of a respective pair of transmitting elements (4a, 4b) and receiving elements (5a, 5b) are deflected via the same beam deflection means and form redundant optical paths and that the light beams (3a, 3b) of different pairs of transmitting elements (4a, 4b) and receiving elements (5a, 5b) are deflected via different, spatially offset beam deflection means and form different, spatially offset optical paths. wherein the transmitter/receiver unit has at least one transceiver which is designed to transmit and receive light beams (3a, 3b), the light beams (3a, 3b) striking the beam deflecting means and being guided from there back to the transceiver, and in which a beam of light beams (3a, 3b) is interrupted when an object is engaged in the monitoring area, and with an evaluation unit in which a binary switching signal (23a, 23b) is generated as a function of received signals of the transceiver, the switching states of which indicate whether an object is present in the monitoring area, wherein redundant optical paths formed by light beams (3a, 3b) are formed in the monitoring area with said at least one transceiver, characterised in that said at least one transceiver has a transceiver controller with a transmit controller controlling at least two transmit elements (4a, 4b) and with a receive controller controlling at least two receive elements (5a, 5b), wherein different optical paths are generated with light beams (3a, 3b) emitted by the transmitting elements (4a, 4b), in that said at least one transceiver controls several pairs of receiving elements (5a, 5b) with its transmitting controller and controls several pairs of receiving elements (5a, 5b) with its receiving controller, wherein the light beams (3a, 3b) of the transmitting elements (4a, 4b) form a multibeam arrangement with redundant optical paths, in that the light beams (3a, 3b) of a respective pair of transmitting elements (4a, 4b) and receiving elements (5a, 5b) are deflected via the same beam deflection means and form redundant optical paths and that the light beams (3a, 3b) of different pairs of transmitting elements (4a, 4b) and receiving elements (5a, 5b) are deflected via different, spatially offset beam deflection means and form different, spatially offset optical paths.