Patent ID: 8820146

Claim:
A cleanliness inspection apparatus for an object to be inspected, the apparatus comprising: an ultrasonic generator tank comprising an ultrasonic generator and containing a first liquid in which ultrasonic waves propagate; a power unit which supplies electric power for producing ultrasonic waves to the ultrasonic generator, and which continues to drive the ultrasonic generator until at least a second time elapses after a lapse of a first time since a start of oscillation of the ultrasonic generator; a particle extraction vessel which contains a second liquid purer than the first liquid and accommodates the to-be-inspected object disposed in the second liquid, and which is adapted to be inserted into the first liquid from above a surface of the first liquid while the ultrasonic waves are being produced in the first liquid contained in the ultrasonic generator tank by the ultrasonic generator after the lapse of the first time; and a particle measuring device configured to measure a quantity of particles contained in the second liquid after the lapse of the second time.