This work describes methods of functions detection in decompilation. It contains basic information about reverse engineering and its applications in computer science and beyond. Decompiler developed by research group Lissom at FIT VUT Brno is introduced. The main objective is to elucidate several methods of functions detection, discuss their advantages and disadvantages, and identify the problems of functions detection. After detecting the start, end and body of function, it is needed to find the parameters and return values. There are some algorithms presented in this area. The output of this thesis is design and implementation of architecture independent function detection and parameter detection.