Scanning Tunnelling Microscopy (STM) is a powerful experimental technique in surface science. It combines atomic resolution imaging with the opportunity to perform nanoscale manipulations. Additionally, STM enable the mapping of the density of states of materials. Here we report first experiments on aza-BODIPY adsorbed on metal surfaces with a newly commissioned lowtemperature STM/AFM-System. Aza-BODIPY are a class of organic fluorescent dyes characterised by the same molecular core. These molecules exhibit strong chemical stability and highly tuneable, sharp absorption wavelength. Aza-BODIPY has previously been used for immunostaining and photodynamic therapy during the last few years. Recently, electron donor materials for organic photovoltaics (OPVs) has emerged as another field of application, due to aza-BODIPYs strong infrared absorption. In this work single aza-BODIPY molecules adsorbed on Au(111) were investigated by STM at 5 K. The adsorption configuration and geometry were determined and found to be in qualitative agreement with theoretical simulations.