Patent ID: 7864310

Claim:
An inspection apparatus, comprising: a scanning system which moves a substrate; a first irradiating unit which irradiates said substrate with approximately perpendicular light; a second irradiating unit which irradiates said substrate with oblique light; a position sensor which detects a first position of said perpendicular light on said substrate and detects a second position of said oblique light on said substrate, said position sensor being provided on said scanning system; a detecting system which detects a light from said substrate, said detecting system including a first high angle detecting unit, a second high angle detecting unit, a first low angle detecting unit and a second low angle detecting unit; and a first processing unit which inspects said substrate responsive to detected light, wherein: said first processing unit classifies a defect and foreign matter by using a combination of: at least one of said first irradiating unit and said second irradiating unit, and at least one of said first high angle detecting unit, said second high angle detecting Unit, said first low angle detecting unit and said second low angle detecting unit; said first high angle detecting unit and said first low angle detecting unit are arranged to detect light propagating substantially in a tangential direction relative to said substrate, the tangential direction corresponding to a direction of diffraction light having weaker intensity than another light propagating in a direction different from the tangential direction; and said first high angle detecting unit and said first low angle detecting unit operate according to said first and second positions detected by said position sensor.