Inspection method based on captured image and inspection device

An inspection apparatus having:

• an illumination unit illuminating a surface of an object under inspection by white light,
• an image capturing unit capturing an image of the surface of said object under inspection, and
• a processing unit obtaining the image captured by said image capturing unit and using said captured image as a basis to perform processing relating to inspection of the state of said object under inspection,
• which inspection apparatus is configured so that
• the apparatus has a polarization member arranged at least at one of a light path by which white light emitted from said illumination unit reaches the surface of said object under inspection and a light path by which reflected light from the surface of said object under inspection reaches said image capturing unit and so that
• said processing unit has a means for acquiring a plurality of captured images from said image capturing unit in a state with said polarization member used to change polarization characteristics of light reaching said image capturing unit and
• can use the relationship between the acquired plurality of captured images and the corresponding polarization characteristics as a basis to judge the state of the surface of said object under inspection.