A method for first forming a conductive filament in a resistive random access memory device, the resistive random access memory device including: - a first electrode, called an "inert electrode"; - a metal oxide solid electrolyte; - a second electrode, called a "soluble electrode", the first and second electrodes being respectively arranged on either side of said metal oxide solid electrolyte, the second electrode being able to provide mobile ions flowing in the metal oxide solid electrolyte to the first electrode to form a conductive filament between the first and second electrodes when a potential difference is applied between the first and second electrodes; - an interface layer comprising a metal oxide, the interface layer extending at least partially on the first electrode, the metal oxide solid electrolyte extending at least partially on the interface layer; the method being characterised in that it comprises: - a so-called "pre-forming" step in which, the resistive random access memory device being in a first insulating state and having a first resistance R1, a first electric potential V1 is applied to the first electrode and a second electric potential V2 is applied to the second electrode, the second electric potential V2 being lower than the first electric potential V1, for forming a localised path of oxygen vacancies between the first and second electrodes, the resistive random access memory device at the end of said pre-forming step being in a second insulating state and having a second resistance R2 lower than the first resistance R1; - a so-called "forming" step in which, the resistive random access memory device being in a second insulating state, a first electric potential V1' is applied to the first electrode and a second electric potential V2' is applied to the second electrode, the second electric potential V2' being higher than the first electric potential V1', for forming the conductive filament between the first and second electrodes, the resistive random access memory device at the end of said forming step being in an ON state. - a first electrode, called an "inert electrode"; - a metal oxide solid electrolyte; - a second electrode, called a "soluble electrode", the first and second electrodes being respectively arranged on either side of said metal oxide solid electrolyte, the second electrode being able to provide mobile ions flowing in the metal oxide solid electrolyte to the first electrode to form a conductive filament between the first and second electrodes when a potential difference is applied between the first and second electrodes; - an interface layer comprising a metal oxide, the interface layer extending at least partially on the first electrode, the metal oxide solid electrolyte extending at least partially on the interface layer; - a so-called "pre-forming" step in which, the resistive random access memory device being in a first insulating state and having a first resistance R1, a first electric potential V1 is applied to the first electrode and a second electric potential V2 is applied to the second electrode, the second electric potential V2 being lower than the first electric potential V1, for forming a localised path of oxygen vacancies between the first and second electrodes, the resistive random access memory device at the end of said pre-forming step being in a second insulating state and having a second resistance R2 lower than the first resistance R1; - a so-called "forming" step in which, the resistive random access memory device being in a second insulating state, a first electric potential V1' is applied to the first electrode and a second electric potential V2' is applied to the second electrode, the second electric potential V2' being higher than the first electric potential V1', for forming the conductive filament between the first and second electrodes, the resistive random access memory device at the end of said forming step being in an ON state.