An apparatus for sterilizing a dialyzer for extracorporeal blood treatment includes a pulsed electric field generator arranged for generating a pulsed electric field penetrating the dialyzer received between a first electrode and a second electrode, when a pulsed electric voltage is applied between the first electrode and the second electrode of the generator. A method of sterilizing a dialyzer for extracorporeal blood treatment adapted to be executed using the apparatus incorporates, in a process for preparing or manufacturing the dialyzer, at least the steps of generating a pulsed electric field using a predetermined number of electric pulses of defined electric voltage, defined pulse duration and defined pulse-off time between the pulses, and applying the pulsed electric field to the dialyzer.
