A microscopic device for three-dimensional localization of point-like objects, encompassing a detection optical system that images point-like objects, each in the form of a three-dimensional focus light distribution, into an image space a color separation apparatus that divides the light into at least two separate light bundles of different wavelength regions at least two image space detector units , one receiving one light bundle and the other receiving the other light bundle, each detector unit comprising a light-spot-sensing detection surface an evaluation unit that ascertains a lateral X-Y position and an axial Z position relative to the sharpness plane in a direction perpendicular to the sharpness plane at least one Z-position correction value for at least one of the wavelength regions being stored in the evaluation unit, which value indicates a detection optical system longitudinal chromatic aberration in that wavelength region and the evaluation unit correcting the Z position.
