A safety device for multi-channel processing of at least two analogue input signals, comprising - a first input device adapted to receive a first analogue input signal, wherein the first input device has at least a first and a second channel and a measuring device adapted to measure the first analogue input signal and to divide it in predetermined manner into a first sub-signal and a second sub-signal, the first sub-signal being supplied to the first channel and the second sub-signal being supplied to the second channel; - an evaluation and control device that can be connected to the first and second channels and which is adapted to monitor the functionality of the first input device in response to the first sub-signal and the second sub-signal; - at least one second input device adapted to receive a second analogue input signal, wherein the second input device has at least a first and a second channel and a measuring device adapted to measure the second analogue input signal and to divide it in predetermined manner into a first sub-signal and a second sub-signal, the first sub-signal being supplied to the first channel and the second sub-signal being supplied to the second channel of the second input device, wherein the evaluation and control device can be connected to the first and second channels of the second input device and is adapted to monitor the functionality of the second input device in response to the first sub-signal and the second sub-signal of the second analogue input signal; - a first switching device and a second switching device, wherein the first channel of the first input device and the first channel of the at least one second input device can be connected to a first input of the evaluation and control device by means of the first switching device, and the second channel of the first input device and the second channel of the at least one second input device can be connected to a second input of the evaluation and control device by means of the second switching device. - a first input device adapted to receive a first analogue input signal, wherein the first input device has at least a first and a second channel and a measuring device adapted to measure the first analogue input signal and to divide it in predetermined manner into a first sub-signal and a second sub-signal, the first sub-signal being supplied to the first channel and the second sub-signal being supplied to the second channel; - an evaluation and control device that can be connected to the first and second channels and which is adapted to monitor the functionality of the first input device in response to the first sub-signal and the second sub-signal; - at least one second input device adapted to receive a second analogue input signal, wherein the second input device has at least a first and a second channel and a measuring device adapted to measure the second analogue input signal and to divide it in predetermined manner into a first sub-signal and a second sub-signal, the first sub-signal being supplied to the first channel and the second sub-signal being supplied to the second channel of the second input device, wherein the evaluation and control device can be connected to the first and second channels of the second input device and is adapted to monitor the functionality of the second input device in response to the first sub-signal and the second sub-signal of the second analogue input signal; - a first switching device and a second switching device, wherein the first channel of the first input device and the first channel of the at least one second input device can be connected to a first input of the evaluation and control device by means of the first switching device, and the second channel of the first input device and the second channel of the at least one second input device can be connected to a second input of the evaluation and control device by means of the second switching device.