DIAGNOSTIC DEVICE FOR ELECTRIC MOTOR

Provided is an electric motor diagnosis device in which, when an electric current from an electric current input unit (71) for detecting an electric current of an electric motor (5) is in a stable state, a power spectrum of the electric current is analyzed by an FFT analysis unit (8402); smoothing is carried out by an averaging calculation unit (8406) on a plurality of charges of power spectrums having been analyzed by the FFT analysis unit (8402); a sideband frequency of a power spectrum having been smoothed thereby is extracted by a sideband frequency extraction unit (8407); and a warning is outputted from a warning output unit (85) when signal intensity of a sideband frequency extracted by the sideband frequency extraction unit (8407) is a preset value or more.