An apparatus for analyzing an element rotating at a rotational speed based on an vibration signal originating from the rotating element has: an analysis function processor for forming a plurality of analysis functions, the analysis function processor configured to form each analysis function based on an analysis frequency, on the vibration signal or on a measured or estimated rotational speed and on a predetermined order factor differing for each analysis function; a correlator configured to calculate a correlation result from the vibration signal and each analysis function, each correlation result being associated to the order factor which the analysis function, with which the correlation result was calculated, is based on, and the correlation results representing a correlation function; and an examiner configured for examining the correlation function or examining information derived from the correlation function so as to make a statement on a state of the rotating element.