Abstract: An apparatus for purifying water, comprising a funnel-shaped member, a sleeve formed integrally with said member, a cup-shaped insert having a cylindrical wall arranged within the sleeve, screen-like closure members at upper and lower ends of the cylindrical wall of the insert, defining an accommodation chamber containing a granular purifying agent which is insoluble in water, the apertures in the screen-like closure members being smaller than the granules of the purifying agent, and a ventilation tube projecting upward and extending above the vertical height of the funnel-shaped member, provided at the top with openings, attached to the screen-like closure member at the upper end of the insert, said ventilation tube serving as a handle for said insert.