A dialysis machine is provided with a dialysate circuit, a blood circuit and a filter having a dialysate compartment connected to the dialysate circuit, a blood compartment connected to the blood circuit, and a semi-permeable membrane to separate the dialysate compartment from the blood compartment. A method for filling and washing the filter includes the recirculation of a physiological saline in the dialysate circuit and the transfer of the physiological saline from the dialysate circuit to the blood circuit through the semi-permeable membrane.