The sole of human foot has nerve points which related to other organs of the body. The soak foot therapy use hot water or cold water is one of the effective therapies to relax and treat part of the disease body The purpose of this research is to design the water bath therapy which has multifunction in utilizing, so the user could choose hot or cold temperature to facilitate the user to do the therapy in one tool which appropriate with the kinds of the patient disease. This tool therapy use peltier as the refrigeration of water, heater as heating of the water, and sensor temperature LM35 waterproof as the detection of water temperature that later will be appear on the display LCD. The results of the experiment is obtained by comparing the temperature of the tool with the temperature on the mercur. From the experiment, this tool is get the highest error 5% on the setting temperature 80o C and the highest error 2.6% on the setting temperature 40oC. The error of the tool is still in the limit tolerance, so this tool proper to be use.