High demand for turbomachinery devices is constantly growing due to the constrains of reduction noise generation, fuel burn and gases emission. Competitiveness on the turbomachinery market forces manufactures to look for possibilities of reducing production costs – using cost-effective machining methods. According to the safety requirements in area of aeronautical industry, it is very important to ensure high geometrical and dimensional accuracy. Because of the very good mechanical properties, high temperature resistance and corrosion resistance, hard to machine nickel based superalloys are commonly used as components of aero engines. Due to the mentioned properties it is very hard to machine heat resisting nickel alloys with conventional machining methods. One of the nonconventional machining methods which is commonly used is electrodischarge machining. The main advantage of this method is that it is possible to machine each material which is an electrical conductor, regardless of its mechanical properties. In this paper the results of electrodischarge drilling of Inconel 625 and Inconel 718 with different values of current intensity and pulse time were presented. There was pointed the relation between current intensity and material removal rate and also correlation between discharge intensity and material removal rate. On the basis of experiment results it is known that Inconel 625 is easier to machine by EDM than Inconel 718. As a result of SEM photos and EDS analysis of the Inconel 718 surface it is possible to say that discharge intensity growth results in occurring bigger and deeper electroerosion craters, microcracks and solidified debris with content of carbon. It is required to expand the research of analysis of changes in Inconel’s 625 surface.