The procedure for the standardization of 59Fe using a 4??(PC)??????? software coincidence system is de-scribed. The standardization was performed with an experimental setup consisting of a thin window gas- flow proportional counter (PC)in4?? geometry coupled to a NaI(Tl) scintillator and to a HPGe detector. The data acquisition was carried out by means of a Software Coincidence System (SCS).The beta efficiency was changed by using Collodion films Colldion films andaluminum foils as external absorbers.