EN
In the economic literature there is a tendency not to define the nature of money, but to specify functions that money is supposed to perform or to assume that these functions are determining the nature of money. The aim of this paper was to demonstrate some controversies arising upon the acceptance of the functional definition of money. The analysis focused on particular (traditionally defined) functions of money (means of payments, store of value, medium of exchange and unit of account). Conducted considerations allowed to attribute fundamental importance to the unit of account function of money.