A method for wavelength-resolving and high spatial resolution fluorescence microscopy in which fluorescence labels in a sample are repeatedly excited to emit fluorescence radiation and frames including images of isolated labels are produced with a microscope. The positions of the images of the isolated fluorescing labels are localized with a localization precision exceeding the optical resolution of the imaging beam path of the microscope. The imaging beam path of the microscope has a diffractive element which, during the imaging, diffracts the image of the sample comprising the isolated fluorescing labels into a first diffraction order so that each frame contains the first diffraction order images of the isolated fluorescing labels. A parameter of the first diffraction order images of the isolated fluorescing labels is evaluated and an indication of the wavelength of the isolated fluorescing labels is derived from this evaluated parameter.