A method for monitoring operation of a power generating installation that has at least one generator that is driven by a rotating machine, in which values of an operating parameter of the generator and/or rotating machine are captured and stored, it is ascertained whether the value of the operating parameter at prescribed checking times lies outside an admissible range, wherein a possible fault is inferred if the value of the operating parameter lies outside the admissible range at two directly successive checking times, an additional check is performed to determine whether the value of the operating parameter is approaching the admissible range in a prescribed checking interval that lies between two directly successive checking times and particularly extends as far as the later of the two checking times, and it is inferred that there is a fault if the value of the operating parameter is not approaching the admissible range.