A dialysis circuit (1； 11； 21； 31) of a dialysis machine operating according to the haemodialysis or haemofiltration technique and comprising a regeneration system (7； 12； 27； 32) of the dialysis solution delivered from the filter or of the ultrafiltrate, to allow re-use thereof respectively as dialysis solution fed into the filter or as reinfusion solution. The regeneration system (7； 12； 27； 32) comprises a filtration device (8； 13； 28； 33) included in the group composed of a nanofiltration filtration device, a microfiltration filtration device or a reverse osmosis filtration device.
