To provide a water purification cartridge and a water purifier, in which the water purifier has a hollow fiber membrane module and the outer surface of a hollow fiber membrane of the hollow fiber membrane module can be cleaned to reduce the running cost when water is purified.

A water purifier 1 has a hollow fiber membrane module 10 which is fixed to one end of a cylindrical case 31 while keeping the ends of a hollow fiber membrane 16 in opened states. A cleaning liquid supply port 40 and a cleaning liquid discharge port 34, which are used for cleaning the outer surface of the hollow fiber membrane, are arranged on the cylindrical case 31. A liquid chemical of the amount enough to fill the cylindrical case 31 therewith is supplied from the cleaning liquid supply port 40, the cleaning liquid discharge port 34 is arranged on the side face of the cylindrical case 31 near a hollow fiber membrane fixed part, and a cleaning on-off valve 38 is arranged on the cleaning liquid discharge port 34. Since the clogged hollow fiber membrane 16 can be regenerated and the water purification cartridge 6 can be used for a long period of time, the running cost can be reduced when water is purified.