Abstract

A water purifier using common advantages of natural and forced types operated without an external electric power source, resulting in high efficiency of water purification. The apparatus for purifying water includes a first water-supply pipe for transporting running water with a predetermined pressure, a second water-supply pipe for pumping the running water to the highest position of the apparatus, a first purifying section for temporarily storing and purifying the water provided by the second water-supply pipe as water flows down by its own gravitational force, a second purifying section for temporarily storing and purifying the water passing through the first purifying section as water flows down by its own gravitation force, and a transparent storage section for storing the water passing through the second purifying section, wherein the first and second purifying sections detect the water levels which fill up from the transparent storage section to the first and/or second purifying sections, thereby control the inflow of water from the second water-supply pipe in accordance with the existing water levels in the first and second purifying sections.