In the method for optical monitoring and/or determination of properties on samples, monochromatic electromagnetic radiation with a predetermined wavelength is sequentially directed from several radiation sources onto a sample influenced by an electronic evaluation unit. The respective intensity specific to the wavelength of the electromagnetic radiation scattered and/or reflected by the sample is detected by at least one detector and fed to the electronic evaluation unit for spectrally resolved evaluation in order to use it to monitor and/or determine properties of the respective sample.