Patent ID: 7224523

Claim:
A scanning optical microscope, compnsing: a light source; a reflection-type wavefront-converting element, which is located such that illuminating light emitted from said light source is incident thereon from an obliqiue direction, and which applies wavefront conversion to said illuminating light as desired; an objective for condensing wavefront-converted illuminating light onto a sample; and a detector element for detecting signal light emitted from said sample, wherein said wavefront converting element is located in an optical path in such a way as to satisfy the following condition (1): θ pr≦ 50 ·NA −1 √{square root over ( )}(λ·Δ Z −1 ) (1) where: θpr: an angle (°) of incidence of a principal ray on said wavefront-converting element; ΔZ: an amount of focal point movement; λ: a wavelength of said illuminating light; and NA: a numerical aperture of said objective.