A facility degradation diagnosis device which diagnoses an electric motor and a machine facility that is driven by the electric motor , the facility degradation diagnosis device, comprising: a transmission-data conversion unit for converting a voltage of the electric motor and an electric current thereof, respectively being detected therefor, into data suitable for transmission; a facility diagnosis unit for diagnosing, based on said data transmitted by way of a communications line , abnormality of the machine facility , wherein the facility diagnosis unit has a machine facility's abnormality diagnosis unit , the machine facility's abnormality diagnosis unit carries out an averaging process on a plurality of analytical results of power spectrums obtained by performing frequency analysis using an electric current waveform when an electric current of the electric motor is stable, detects sideband frequencies from analytical results of power spectrums on which the averaging process has been carried out, and determines the presence or absence of abnormality of a machine facility being a load in accordance with spectrum's peaks in a row; a failure portion/factor estimation unit for estimating a failure region and/or a failure factor thereof based on a result diagnosed by the facility diagnosis unit ; a failure treatment method selection unit for selecting a failure treatment method based on a result obtained by the failure portion/factor estimation unit ; and a display unit for displaying a failure region and/or a failure factor thereof obtained by the failure portion/factor estimation unit , and for displaying a failure handling method obtained by the failure treatment method selection unit . a transmission-data conversion unit for converting a voltage of the electric motor and an electric current thereof, respectively being detected therefor, into data suitable for transmission; a facility diagnosis unit for diagnosing, based on said data transmitted by way of a communications line , abnormality of the machine facility , wherein the facility diagnosis unit has a machine facility's abnormality diagnosis unit , the machine facility's abnormality diagnosis unit carries out an averaging process on a plurality of analytical results of power spectrums obtained by performing frequency analysis using an electric current waveform when an electric current of the electric motor is stable, detects sideband frequencies from analytical results of power spectrums on which the averaging process has been carried out, and determines the presence or absence of abnormality of a machine facility being a load in accordance with spectrum's peaks in a row; a failure portion/factor estimation unit for estimating a failure region and/or a failure factor thereof based on a result diagnosed by the facility diagnosis unit ; a failure treatment method selection unit for selecting a failure treatment method based on a result obtained by the failure portion/factor estimation unit ; and a display unit for displaying a failure region and/or a failure factor thereof obtained by the failure portion/factor estimation unit , and for displaying a failure handling method obtained by the failure treatment method selection unit . <EOS>