In the course of this thesis the effect of aluminium on the tribological properties of high speed steels was investigated. High speed steels are prefentialy used as cutting tools in metal-working industries. Thus tribology is of particular importance. Due to friction, considerable heat develops during cutting. Therefore, high speed steels have to be extremely wear resistant at elevated temperatures. In this thesis the friction and wear properties of high speed steels, Böhler S600 (HSS 6-5-2) and Böhler S630 (HSS 4-4-2) were investigated. Böhler S630 was tested in three variants with different aluminium content (0, 0.5, and 1%), to analyze the effect of aluminium on the tribological properties. The friction behavior was investigated by means of pin-on-disc-tests at different temperatures. The tribometer-tracks were characterized with a (white-light) confocal microscope and a scanning electron microscope. To investigate the influence of aluminium on the oxide-layer on the surface, X-ray photoelectron spectroscopy (XPS) was carried out. Quantitative image analysis was conducted to determine the carbide content of the samples. The results showed no clear evidence that aluminium directly influences the friction and wear behaviour. Furthermore, the X-ray photoelectron spectroscopy showed that in the oxide-layer on the surface, aluminium is not present. In terms of the carbide content, it was observed that with increasing aluminium content carbide content of MC types increases and the M6C type stays constant. This is an possible explanation for the improved properties.