Patent ID: 8059269

Claim:
A particle inspection apparatus comprising: an irradiation unit configured to apply a light beam onto each of front and back surfaces of an object to be inspected, the object including a transparent member; a first detection unit configured to detect scattering light from the front surface; a second detection unit configured to detect scattering light from the back surface; a calculation unit configured to conduct a particle inspection on the front and back surfaces on the basis of outputs from the first detection unit and the second detection unit; and a control unit configured to control the irradiation unit, the first detection unit, the second detection unit, and the calculation unit, wherein the irradiation unit includes a light-shielding selection unit configured to selectively block the light beam applied to the front surface or the light beam applied to the back surface, and wherein the control unit causes the light-shielding selection unit to simultaneously apply the light beam onto the front and back surfaces, determines whether the light beam should be selectively applied onto the front surface or the back surface based on outputs made by the first detection unit and the second detection unit corresponding to simultaneous application of the light beam, causes the light-shielding selection unit to selectively apply the light beam onto the front surface or the back surface when it is determined that the light beam should be selectively applied, and causes the calculation unit to conduct the particle inspection based on outputs made by the detection unit corresponding to selective application of the light beam.