To accurately and rapidly evaluate components for an image forming apparatus, units made up by assembling the components, and units or components retrieved by recycling.

In the method of evaluating the units and the components for the image forming apparatus, an external force is applied on the component for the image forming apparatus and/or the unit made up by assembling the components, thereby generating impact sounds, and generated vibrations are detected by a microphone or a vibration sensor, and then a multiple resolution analysis is carried out for detected signals, and the component for the image forming apparatus and the unit made up by assembling the components are evaluated based on at least analyzed results.