The invention relates to a method for state monitoring of a coil that is part of a device for determining at least one process variable of a medium in a containment. The method includes supplying the coil with an electrical excitation signal and receiving an electrical, received signal from the coil, ascertaining a first frequency for the excitation signal, in the case of which a first phase shift between the excitation signal and received signal is less than a predeterminable limit value, and ascertaining a state indicator for the coil based on the first frequency. Further disclosed is a device embodied for performing a method of the invention.