To provide the quantitative supplier which can discharge the solution in a subtank by a certain amount by pooling a necessary amount of solution automatically in a float without using any driving force and flushing water to a passing pipe (e.g. washer for toilet) for solution.

The float 3 floating in a storage tank 2 containing the solution and the subtank 4 installed outside the storage tank are connected by a connecting pipe and the solution is supplied to the subtank 4 by a certain amount and also discharge by a certain amount. This quantitative automatic supplier 1 is provided with a suction pipe for sucking the solution up at the bottom part of the float body, a wick for solution suction is put in the suction pipe, and an air intake pipe is provided on the float body; and the solution is sucked up into the float body from the wick by capillarity and the suction stops when the solution fills the lower end of the air intake pipe, thus constituting the float 3.