Method for testing a field device, wherein the field device - has a multiplicity of analogue inputs (E200a, E200b, E200c) for feeding in an analogue measurement signal (Ma1, Ma2, Ma3, Ma4, Ma5, Ma6) that relates to an electrotechnical installation to be monitored, - has an external communication interface for feeding in digital measurement signals, and - has a digitally operating evaluation apparatus connected to the analogue inputs (E200a, E200b, E200c) in each case via an A/D converter unit and respective digital signal inputs and to the external communication interface, which evaluation apparatus, if the input-side analogue measurement signal is applied, evaluates it and generates a fault signal if the measurement signal indicates a fault in the electrotechnical installation to be monitored, wherein - a test apparatus, internal to the device and connected to the evaluation apparatus on the one hand and to the external communication interface on the other hand, of the field device generates a digital test signal (Te) itself and - the test apparatus internal to the device, after a test mode is started, feeds the digital test signal as measurement signal into the evaluation apparatus in order to test the field device, wherein - external fault value records are transmitted into the test apparatus via the external communication interface and - the test apparatus internal to the device uses the fault value records to generate the digital test signals (Te) by using the data from the external fault value record to form digital sample values that correspond to converter data, recorded during the fault value recording, of at least one converter, and using these to test the field device; and - the test apparatus internal to the device, when performing the test mode, stores the test signal applied to the evaluation apparatus and the corresponding response of the field device thereto in the form of a fault record. - has a multiplicity of analogue inputs (E200a, E200b, E200c) for feeding in an analogue measurement signal (Ma1, Ma2, Ma3, Ma4, Ma5, Ma6) that relates to an electrotechnical installation to be monitored, - has an external communication interface for feeding in digital measurement signals, and - has a digitally operating evaluation apparatus connected to the analogue inputs (E200a, E200b, E200c) in each case via an A/D converter unit and respective digital signal inputs and to the external communication interface, which evaluation apparatus, if the input-side analogue measurement signal is applied, evaluates it and generates a fault signal if the measurement signal indicates a fault in the electrotechnical installation to be monitored, wherein - a test apparatus, internal to the device and connected to the evaluation apparatus on the one hand and to the external communication interface on the other hand, of the field device generates a digital test signal (Te) itself and - the test apparatus internal to the device, after a test mode is started, feeds the digital test signal as measurement signal into the evaluation apparatus in order to test the field device, wherein - external fault value records are transmitted into the test apparatus via the external communication interface and - the test apparatus internal to the device uses the fault value records to generate the digital test signals (Te) by using the data from the external fault value record to form digital sample values that correspond to converter data, recorded during the fault value recording, of at least one converter, and using these to test the field device; and - the test apparatus internal to the device, when performing the test mode, stores the test signal applied to the evaluation apparatus and the corresponding response of the field device thereto in the form of a fault record. - external fault value records are transmitted into the test apparatus via the external communication interface and - the test apparatus internal to the device uses the fault value records to generate the digital test signals (Te) by using the data from the external fault value record to form digital sample values that correspond to converter data, recorded during the fault value recording, of at least one converter, and using these to test the field device; and - the test apparatus internal to the device, when performing the test mode, stores the test signal applied to the evaluation apparatus and the corresponding response of the field device thereto in the form of a fault record.