Patent ID: 8760757

Claim:
An incident-light fluorescent illumination device comprising: a light source emitting illumination light; a collector lens receiving the illumination light from the light source; a fly-eye lens optical system receiving the illumination light from the collector lens; an objective emitting the illumination light to a sample surface; and a relay optical system arranged between the fly-eye lens optical system and the objective, wherein: the fly-eye lens optical system comprises a first fly-eye lens surface and a second fly-eye lens surface each having a plurality of lens elements; and a conditional expression of 0.3 ≦D 0 /Lob ≦0.75 is satisfied where: D 0 indicates a distance between a conjugate position with the second fly-eye lens surface through the relay optical system and a pupil position of the objective, and Lob indicates a parfocalizing distance of the objective.