A softening apparatus including an ion exchanger that is repeatedly regenerated using electrolyzed hydrogen ions (H+). The softening apparatus includes a regeneration unit configured to produce regeneration water including hydrogen ions (H+) by electrolyzing water, a softening unit including an ion exchanger regenerated by receiving the regeneration water and configured to convert raw water including hardness components into soft water, and a controller configured to control the regeneration unit to produce regeneration water having a pH of 2 to 4. The ion exchanger has a Si/Al ratio of 1 to 5 and includes an inner pore with a diameter greater than 4 nm.