PURPOSE: To obtain a portable water conditioning device which can make simply reduction water having a low oxidation-reduction potential in home or on a trip and to provide the method for producing reduction water.

CONSTITUTION: In a device, a device main body 1 and an electrode part 2 are formed separately and connected electrically, the main body 1 is equipped with a power part, a switch part 12, and a timer part 13, three electrode sticks 21-23, which are located closely to each other, are stretched freely detachably from the electrode part 2 in the electrode part.