A machine component diagnosis system comprising a vibration analyzer configured to analyze a vibration of a machine component and an information terminal configured to transmit and receive a signal to and from the vibration analyzer , the vibration analyzer comprising: a vibration sensor configured to detect a vibration of the machine component ; a filter processing unit configured to extract a predetermined frequency band from a waveform of a signal detected by the vibration sensor ; a calculation processing unit configured to obtain spectrum data from the waveform in the predetermined frequency band; and a transmitting and receiving unit configured to receive an operation command signal from the information terminal and to transmit a signal obtained as a result of the operation to the information terminal ; wherein the information terminal comprises: a diagnosis unit configured to compare a frequency component, which is included in the spectrum data transmitted from the transmitting and receiving unit of the vibration analyzer , and a damaging frequency component generated by the machine component in a damaged state, and to diagnose abnormality of the machine component ; and a display unit configured to output a diagnosis result diagnosed by the diagnosis unit , and characterized in that the information terminal is a portable information terminal connectable with a host computer of headquarters and the machine diagnosis system is configured to detect the driving sound of the machine component , that the filter processing unit is configured to extract a specific frequency band in which the sound detection is intended, that the calculation processing unit is configured to calculate a FFT waveform of the vibration signal on the basis of a FFT algorithm and that the driving sound corresponding to the calculated FFT waveform is reproduced by a speaker . a vibration sensor configured to detect a vibration of the machine component ; a filter processing unit configured to extract a predetermined frequency band from a waveform of a signal detected by the vibration sensor ; a calculation processing unit configured to obtain spectrum data from the waveform in the predetermined frequency band; and a transmitting and receiving unit configured to receive an operation command signal from the information terminal and to transmit a signal obtained as a result of the operation to the information terminal ; wherein the information terminal comprises: a diagnosis unit configured to compare a frequency component, which is included in the spectrum data transmitted from the transmitting and receiving unit of the vibration analyzer , and a damaging frequency component generated by the machine component in a damaged state, and to diagnose abnormality of the machine component ; and a display unit configured to output a diagnosis result diagnosed by the diagnosis unit , and characterized in that the information terminal is a portable information terminal connectable with a host computer of headquarters and a diagnosis unit configured to compare a frequency component, which is included in the spectrum data transmitted from the transmitting and receiving unit of the vibration analyzer , and a damaging frequency component generated by the machine component in a damaged state, and to diagnose abnormality of the machine component ; and a display unit configured to output a diagnosis result diagnosed by the diagnosis unit , and characterized in that the machine diagnosis system is configured to detect the driving sound of the machine component , that the filter processing unit is configured to extract a specific frequency band in which the sound detection is intended, that the calculation processing unit is configured to calculate a FFT waveform of the vibration signal on the basis of a FFT algorithm and that the driving sound corresponding to the calculated FFT waveform is reproduced by a speaker . <EOS>