To provide a water modifying apparatus which prevents electrodes from being broken from their middle part, and can lengthen the maintenance period of the electrodes by changing the impressed current density between the electrodes facing each other.

The water modifying apparatus has an electrolytic cell 11 into which water to be modified is introduced, first and second electrodes 12, 13 which are made of a conductive metal and disposed in the electrolytic cell 11 so as to face each other, one or more intermediate electrodes 14 which are made of a magnesium material and disposed between the first and second electrodes 12, 13, and a voltage impression circuit 15 which impresses a voltage between the first and second electrodes 12, 13, and modifies water in the electrolytic cell 11 alkaline by impressing the voltage between the first and second electrodes 12, 13 to elute Mg2+ ions from the intermediate electrodes 14. The intermediate electrode 14 is structured so that its thickness is gradually increased toward the downstream side of the flow of the water to be modified, thereby preventing the intermediate electrode 14 from being broken from the middle part and lengthening the maintenance period of the electrode.