In an evaluation apparatus of a hub unit, a signal processing unit outputs frequency analysis signals which indicate such a result obtained by that an output signal of an acceleration sensor fixed on a hub unit by a magnet is processed via an A/D converting unit and an envelope detecting unit, and thereafter, the processed sensor signal is analyzed for a frequency analysis by an FFT unit. Then, an evaluation output unit evaluates damage conditions of the hub unit based upon signal strengths of specific frequencies, and overall values, which are acquired from the frequency analysis signals, and then, outputs the evaluated damage condition to a display unit.