Nanomechanical resonators have been shown to have a huge field of application because of their extraordinary properties, ranging from atomic force microscopy to mechanical qubits [1,2]. A special property of these nanomechanical resonators is their photothermal frequency response: The absorbed power of a light source with defined wavelength will cause a shift in the resonance frequency of the resonator (Fig. a). Hence, by adding molecules or proteins as absorbers, this can be used for spectroscopy applications [3]. Figure 1: (a) Schematic: Absorbed laser power resulting in a change of resonance frequency. (b) A photothermal scanning microscopy image of two Atto633 accumulations. (c) Measured absorption spectrum and reference spectrum of Atto633. In our method, we are using a highly focused UV-Vis light source in combination with a scanning stage to reach spatially resolved images of Atto633 (Fig. b). Furthermore, by changing the wavelength of the light source, a full UV-Vis spectrum of each point on the resonator can be obtained and finally translated back into an absorption spectrum (Fig. c). Since this method offers both spectral and spatial resolution of the target substance, it is a promising alternative to more established spectroscopy methods. We present a full experimental setup realizing photothermal scanning microscopy and spectroscopy covering a spectral range from ultraviolet to near infrared on the example of the well-known color agent Atto633 as a proof of concept for this method. Our method was able to resolve several femtograms of Atto633 promising to reach even lower concentrations in the near future with the final goal of single molecule and protein resolution. This work is part of the collaboration project MASMONADE funded by Novo Nordisk