PURPOSE: To control opening/closing of an water amt. setting valve and the amt. of water according to the purpose of use with a microcomputer by assembling the water amt. setting valve and a water temp. sensor between the main body of the ion water producing device and the tap of city water.

CONSTITUTION: This ion water producing device 1 is used to produce ion-water by introducing city water from a tap 11 to purifying device 2 and electrolytic cell 3 in the main body of the ion water producing device l. This device is equipped with a water amt. setting valve between the tap 11 of the city water and the main body l of the device to set the water amt. of city water to be introduced, water pressure sensor in the city water tap side of the valve, and water temp. sensor 18 on the tap side of the sensor. Also, this device is equipped with a controlling unit 4 having a controlling part and an indicating part 8 which indicates the result of setting. In the controlling part, opening/closing of the water amt. setting valve and operation of the electrolytic cell 3 are controlled according to the results of detection of the water pressure sensor 17 and the water temp. sensor 18 and to the setting of the operational setting part.