To stimulate and treat one foot with natural posture without forcing a unnatural posture, when treating one foot only, for a vortex bath device of stimulating an affected part by sliding a seat part that is for patient' sitting down set adjacent to the bathtub.

Taking in hot water or water from bathtub 2 or other supply source for hot water with a pump, it is jetted from a nozzle 4. The nozzle 4 is connected with an air pipe, and when jetting hot water or water from the nozzle 4, air is taken from the air pipe at the same time, then mixing hot water and the like with taken air, it is jetted from the nozzle 4. As a heater 5 is done the on/off control or the proportional control with the signal from the control part, the temperature of hot water stored in the bathtub 2 is controlled to keep at the predetermined value. A seat part 9, which is set at the upper part of vortex bath device 1, is enabled to slide to right and left sides through the roller set at the lower face. The movement to side direction of seat part 9 is controlled with a stopper 11.