A fluorescence scanning microscope includes excitation and de-excitation light sources, which are designed to generate an excitation and a de-excitation light distribution, respectively. An illumination unit combines the light distributions to form a light distribution scanning over multiple illumination target points of a sample in such a way that an intensity maximum of the excitation light distribution and an intensity minimum of the de-excitation light distribution are spatially superimposed on one another. A detector detects fluorescence photons emitted from the respective illumination target point as a function of their arrival times. A processor evaluates the fluorescence photons with respect to the arrival times, generates a first pixel and a second pixel based thereon, assembles the first and second pixels to form first and second sample images, respectively, and, by means of the two sample images, determines a spatial offset between the intensity maximum and the intensity minimum.