To accomplish new structure for a drain quantity varying device, which can surely generate a siphoning action and hardly causes an error operation, so as to provide a highly durable liquid purifier surely performing a purifying action as to the drain quantity varying device which uses a siphoning action and is suitably built in the purifier for an appreciation purpose water tank.

In a discharge chamber 51, a drain pipe 52 passing through the bottom face, an intake pipe 53 adjacent to the drain pipe 52, and a covering container 54 covering the drain pipe 52 and the intake pipe 55 from the upper side are formed. An upper opening 52a of the drain pipe 52 and a water sucking port 53 of the intake pipe 53 are formed at the same height substantially, and a lower part opening 52b of the drain pipe 52 is sunk below a water surface of a water tank 30.