Protective device for protecting an electrotechnical system (100, 200, 300), in particular for protecting an electrical energy supply system, wherein the protective device comprises a plurality of measurement inputs and a plurality of function modules (FM1-FM4, FS1-FS2), which can be connected to the measurement inputs by means of a setting of the protective device on the part of the user in such a way that the function modules implement protection functions defined on the part of the user and can output corresponding control signals (ST, ST2) for switching on or off assigned switches (110, 210, 230, 310) of the electrotechnical system, wherein - the protective device makes available function groups (FGM, FGM1, FGM2, FGS, FGS1, FGS2), to which in each case one or a plurality of function modules (FM1-FM4, FS1-FS2) can be assigned in the context of the setting of the device, wherein the protective device provides at least two different function group types, of which at least one function group type (FGS, FGS1, FGS2) is switch-specific and at least one function group type (FGM, FGM1, FGM2) is protection-specific, characterized in that - exclusively switch-specific function modules (FS1-FS2) can be assigned to a switch-specific function group (FGS, FGS1, FGS2) and exclusively protection-specific function modules (FM1-FM4) can be assigned to a protection-specific function group (FGM, FGM1, FGM2), wherein the protection-specific function modules (FM1-FM4) are configured to evaluate voltage and/or current measurement variables present at the protective device on the input side, or measurement values derived therefrom, and generate error signals if errors are identified, and wherein the switch-specific function modules (FS1-FS4) are configured, given the presence of error signals of upstream protection-specific function modules, to switch off the switches assigned to the respective switch-specific function module (FS1-FS4) in accordance with the manner defined in the switch-specific function module (FS1-FS4) and, if appropriate, to switch on said switches again at a later point in time. - the protective device makes available function groups (FGM, FGM1, FGM2, FGS, FGS1, FGS2), to which in each case one or a plurality of function modules (FM1-FM4, FS1-FS2) can be assigned in the context of the setting of the device, wherein the protective device provides at least two different function group types, of which at least one function group type (FGS, FGS1, FGS2) is switch-specific and at least one function group type (FGM, FGM1, FGM2) is protection-specific, characterized in that - exclusively switch-specific function modules (FS1-FS2) can be assigned to a switch-specific function group (FGS, FGS1, FGS2) and exclusively protection-specific function modules (FM1-FM4) can be assigned to a protection-specific function group (FGM, FGM1, FGM2), wherein the protection-specific function modules (FM1-FM4) are configured to evaluate voltage and/or current measurement variables present at the protective device on the input side, or measurement values derived therefrom, and generate error signals if errors are identified, and wherein the switch-specific function modules (FS1-FS4) are configured, given the presence of error signals of upstream protection-specific function modules, to switch off the switches assigned to the respective switch-specific function module (FS1-FS4) in accordance with the manner defined in the switch-specific function module (FS1-FS4) and, if appropriate, to switch on said switches again at a later point in time.