In this paper I am analyzing Peter Unger's famous argument in favour of mereological nihilism (according to this view elementary particles are the only existing objects), called: 'Sorites of Decomposition'. This argument is based on the fact that we can remove one, single atom from a compound object without making it ceased to exist. First I present different versions of Sorites of Decomposition and different ways of rejecting this argument - like appealing to common sense or essential properties. Finally I argue that one of the premises from the original version of the argument is obviously false - we cannot always remove one single atom from an object without making it ceased to exist.