PURPOSE: To decide the exhanging time of a cartridge with a simple structure by furnishing an outer shell for covering the treating part such as activated carbon and a filter and a water purifying cartridge to a body, and providing a window at a position from where the cartridge of the outer shell for the filter can be seen.

CONSTITUTION: When the purified water is taken out, an O ring 25 is brought into contact with the circular arc surface of the leading end 20d of a spool sleeve 20 by pulling a dial part 22, and the communicating part 7i on the inlet side of a vertical water passage 7 is communicated with the part of a horizontal water passage 7c at the right of the spool sleeve 20. Under such conditions, when a water tap 1 is opened, the original water enters the purified water inlet passage 7e, flows in the direction as indicated by the dottedline arrow, passes through a purified water introducing passage 10a and the hole 13a of a presser 13 for activated carbon, and enters the inside of the activated carbon 14. The water is purified in this part, and the water purified by passing through a filter 5 is taken out as the purified water from a purified water outlet passage 7k to the outside.