We suggest a method of water demineralization by electrodialysis with ion-exchange membranes and ion-conducting nets made of ion-exchangers and polyethylene compositions The net meshes are filled with the grains of ion-exchangers. This method makes it possible to produce pure water with specific electrical resistance about 3 M Omega .cm from water treated by reverse osmosis (specific electrical resistance 30k Omega .cm) at low power consumption.