Abstract: A filter-press type electrodialysis apparatus imparts excellent uniform distribution of the liquid within the diluting and concentrating cells and low leakage of the liquid between the cells due to the fact that the liquid feeding or discharging means of the cells are formed separately from the body of the cell frame and of a rigid material having a thickness not more than and preferably less than the thickness of the cell frame body, which is formed of an elastic material, whereupon assembly of the elements, the cell frames are compressed together while the feeding or discharging means are substantially non-compressed, thereby preventing leakage.