PURPOSE: To exhibit excellent water purification action in a long period and also to realize compaction by forming a water channel of a long flow path which connects the interval between a water supply port and a water flow port and is spirally curved in the inside of a closed case body and packing a water purifying filter medium in the water channel.

CONSTITUTION: In the case of applying a water purifying plant to a domestic water purifier, a water purifier main body 1 is constituted of the upper reception part 2, a filter part 3 and the lower reception part 4. The upper reception part 2 is formed into a closed-end box so that water can be stored in order to supply city water to the filter part 3. An outflow nozzle is provided in one side part of the bottom wall 21 thereof. Further, the filter part 3 is formed into a case body of a closed state. A water supply port 32 for introducing an outflow nozzle 22 is bored in one side part of the upper wall 31. Moreover, the bottom wall 33 is tilted in a funnel shape and a water flow port 34 is bored in the central part. The water channel 36 of a long flow path which is formed of a spiral partition 35 and curved is provided so as to connect the interval between the water supply port 32 and the water flow port 34. A water purification filter medium 37 is properly packed in the water channel 36. Water passed through the water channel 36 is filtered and purified.