The aim of this article is to describe the legal regime of the natural resources of celestial bodies. In recent months and years, there has been an increase in debates regarding mining on the moon and asteroids. This article is dedicated to the analysis of the legal regime of such activities. In particular, whether such activities are possible from the point of view of international law, how they are regulated and what are the potential future developments in this area. The article offers an analysis and comparison of the legal regime governing the natural resources of celestial bodies based on the Outer Space Treaty and the Moon Agreement, respectively. The Moon Agreement is given special attention despite its limited international significance, and arguments are presented in favour of its possible recognition by more states in the future. In both cases, arguments are presented that the non-appropriation principle regarding the outer space and celestial bodies, as expressed in both international treaties, does not apply to the natural resources.