An Inspection apparatus and method includes utilizing an emitter which
emits a light beam, an illumination optical system, a detection optical
system, and a processor. The illumination optical system includes a
polarization controller, a coherence reducer, and an objective lens, for
illuminating a specimen with a polarization condition controlled and
coherency reduced light beam through the objective lens. The detection
optical system includes an imaging lens and a sensor for detecting an
image of the specimen illuminated by the light beam through the
illumination optical system. The processor processes a signal outputted
from the sensor and detects a defect on the specimen.