A rotating machine abnormality detection device which detects abnormality in a rotating machine having at least a first rotating body and a second rotating body which rotate around respective predetermined shafts while engaging with each other with a predetermined gap provided therebetween in a normal state, the device comprising: a vibration measurement unit which measures vibration caused by at least one of the first and second rotating bodies ( 81-1, 81-2); a spectrum processing unit which obtains a frequency spectrum of measurement data measured by the vibration measurement unit; a feature amount processing unit which obtains a predetermined feature amount related to a predetermined frequency component, based on the frequency spectrum obtained by the spectrum processing unit; an abnormality determination unit which determines presence/absence of abnormality in the rotating machine, based on the predetermined feature amount obtained by the feature amount processing unit; an characterised by a noise determination unit which when determination is made that abnormality is present by the abnormality determination unit, determines, based on the frequency spectrum obtained by the spectrum processing unit, whether the determination of abnormality is caused by noise being superimposed on an output of the vibration measurement unit or not, wherein when the noise determination unit determines that the determination of abnormality is not caused by the noise, the abnormality determination unit ultimately considers the determined abnormality as abnormality, wherein the rotating machine abnormality detection device further comprises a storage unit which stores, as a normal frequency spectrum, the frequency spectrum of measurement data measured by the vibration measurement unit, when the abnormality determination unit determines that abnormality is absent, wherein the noise determination unit determines whether the determination of abnormality is caused by noise or not, based on a difference between the frequency spectrum obtained by the spectrum processing unit and the normal frequency spectrum stored in the storage unit, and the noise determination unit determines whether the determination of abnormality is caused by noise or not, based on a subtraction result obtained by subtracting an average value of the difference from a maximum value of the difference, or based on a subtraction result obtained by subtracting an intermediate value of the difference from a maximum value of the difference. a vibration measurement unit which measures vibration caused by at least one of the first and second rotating bodies ( 81-1, 81-2); a spectrum processing unit which obtains a frequency spectrum of measurement data measured by the vibration measurement unit; a feature amount processing unit which obtains a predetermined feature amount related to a predetermined frequency component, based on the frequency spectrum obtained by the spectrum processing unit; an abnormality determination unit which determines presence/absence of abnormality in the rotating machine, based on the predetermined feature amount obtained by the feature amount processing unit; an characterised by a noise determination unit which when determination is made that abnormality is present by the abnormality determination unit, determines, based on the frequency spectrum obtained by the spectrum processing unit, whether the determination of abnormality is caused by noise being superimposed on an output of the vibration measurement unit or not, wherein when the noise determination unit determines that the determination of abnormality is not caused by the noise, the abnormality determination unit ultimately considers the determined abnormality as abnormality, wherein the rotating machine abnormality detection device further comprises a storage unit which stores, as a normal frequency spectrum, the frequency spectrum of measurement data measured by the vibration measurement unit, when the abnormality determination unit determines that abnormality is absent, wherein the noise determination unit determines whether the determination of abnormality is caused by noise or not, based on a difference between the frequency spectrum obtained by the spectrum processing unit and the normal frequency spectrum stored in the storage unit, and the noise determination unit determines whether the determination of abnormality is caused by noise or not, based on a subtraction result obtained by subtracting an average value of the difference from a maximum value of the difference, or based on a subtraction result obtained by subtracting an intermediate value of the difference from a maximum value of the difference.