Constant temperature liquid bath

The present invention provides a constant-temperature liquid tank capable of easily performing the heat exchange between a heat source and the liquid, efficiently keeping a constant-temperature of the liquid, and easily and quickly adjusting the temperature even when a dipped article of which the temperature is to be controlled, exists in the tank, with respect to the constant-temperature liquid tank using a thermo module. This constant-temperature liquid tank 1A where the temperature of the liquid in the tank is adjusted by a heat supply device 9 comprising the thermo module 31 adjusting the temperature by Pertier effect, comprises an outer tank 3 for storing the liquid, an inner tank 5 mounted inside of the outer tank through a clearance 17, having a through hole 21 on its side wall 19 for allowing the liquid to flow therein from the outer tank and having a hole 25 on a center of a bottom part 23, and a stirring machine 7 for guiding the liquid flowing from the hole of the bottom part of the inner tank thro