Water purifier filtration portion, water purifier main body, and water purifier including the both

A water purifier is composed of a valve main body and a filtration portion, which are coupled to each other in an attachable and detachable manner at the main body side coupling portion and the filtration portion side coupling portion. Consequently, the water purifier filtration portion can be connected to the water purifier main body in a single step with ease in a secure manner, and at the same time, the water purifier filtration portion will not fall off easily even when water with a high water pressure flows in. Also, the water purifier is provided with a concave portion and a sensor packing formed as an integral portion of the concave portion and protruding toward an indicator portion on a wall surface of a cartridge. The indicator portion is provided with a conductive member at a position where it is brought into contact with a first input portion by a water pressure and thereby closes an electric circuit on a circuit board. Consequently, the service life (the rated service cycle) of a filter material (medium) can be notified to the user accurately, and a fluid-tight condition of the indicator portion and the cartridge portion can be ensured.