An electrodeionization device having an improved boron rejection capability compared with high-performance electrodeionization devices proposed in the related art is provided. An electrodeionization device comprising a cathode; an anode; and a plurality of cation-exchange membranes and a plurality of anion-exchange membranes, the plurality of cation-exchange membranes and the plurality of anion-exchange membranes being arranged between the cathode and the anode so as to form concentrating compartments and desalting compartments, the concentrating compartments and desalting compartments being arranged alternately, the desalting compartments being filled with an ion-exchange resin, wherein the ion-exchange resin has an average particle size of 100 to 300 μm. Preferably, the ion-exchange resin has a uniformity coefficient of 1.1 or less.