PURPOSE: To completely purify the beverage containing the microorganisms harmful to the human body at low costs by providing an ion producing means, an aragonite water treating means, a granular active carbon water treating means and a long life filter water treating means.

CONSTITUTION: An ion producing means 300 activates water quality and removes harmful components such as residual chlorine. An aragonite water treating means 400 removes further the residual chlorine to change the acidic water into the alkaline water. A granular active carbon water treating means 500 removes bleaching powder and the trihalomethane being a carcinogen to reduce the residual chlorine in the water to at most 0.1ppm, thereby protecting a long life filter water treating means 100. In this means 100, since a filter chamber 10 having a water inlet 11 and a water outlet 12 is divided by a filter 20 into an upstream and a downstream side, the water is filtered to remove various bacteria and suspended matter therefrom. An aeration means 30 is also provided on the downstream side of the aforesaid filter chamber 10 in order for the filter to be prevented from clogging by backwashing operation.