Abstract: A confocal scanning microscope comprises rotational disk having numerous pinholes arranged at positions that are conjugate with respect to an object to be observed, illumination optical system for implementing the pinhole-illumination for the object to be observed through the rotational disk, and observation optical system for conducting a reflected light beam from the illuminated object to be observed through the rotational disk and focuses the light beam to form an image for observation at a position that is conjugate with respect to the rotational disk, wherein the pinholes of the rotational disk are in equiangular arrangement on a parabolic spiral. The number of loops M of the parabolic spiral and the number of equiangular divisions in one round of the parabolic spiral at which the pinholes are located have any of relations: M:N=1:2, 3:2, 5:2, . . . , (2i-1):2, where i is an integer.