A measuring device for measuring the power of a high-frequency signal including a detector for detecting the high-frequency signal and for generating an analog detector signal, an analog/digital converter for generating a digital signal and an evaluation device for evaluating the digital signal. A dither supply device for the supply of a dither signal and a chopper, which periodically chops the analog detector signal with a chopper signal, are disposed between the detector and the analog/digital converter. In this context, the dither signal is supplied synchronously to the chopper signal.