The requirements of the working and safety norms demonstrate significant need of increased efficiency and improved working conditions in cleaning confined spaces. This paper presents an overview of the existing technologies and solutions for cleaning large confined spaces. A special attention is directed for cleaning interior surface of confined spaces used mainly for storing bulk materials or liquids, such as silos. The cleaning technologies for confined space depend on several aspects as the build-up material, the surface material, the ambient conditions. Four cleaning techniques are presented in this paper. The mechanisms and robots related to the studied problem are surveyed and evaluated from the viewpoint of their capability to clean interior surfaces. The dominating majority of the existing cleaning equipment is constructed to serve cleaning the entire volume of the respective confined space (silo), but not for cleaning the interior surface.