A field device is composed of a sensor, which works according to a defined measuring principle, and a control/evaluation unit, for a particular safety-critical application, conditions and evaluates, along at least two equivalent measuring paths, measurement data delivered by the sensor. The control/evaluation unit is implemented on an FPGA, provided with at least a first section and a second section. In each section, a digital measuring path, is dynamically reconfigurable. The sections are isolated from one another by permanently configured spacer regions, wherein the spacer regions are embodied in such a way, that a temperature and/or a voltage change in one of the sections has no influence on the other section or other sections, and, in the case of malfunction, no connection occurs between the sections. The control/evaluation unit, as a function of the particular defined safety-critical application, partially dynamically reconfigures the function modules in the measuring paths in such a manner, that the field device fulfills the required safety standard.