To enable the decomposition of the stains of the feet or the like and the elimination of the bacilli therein and prevent water in a bath tub from spilling.

The foot bath is provided with the bath tub 6 arranged within the case 1 of a main body installed on a floor or the like, an electrolytic water generator 14 for supplying electrolytic water into the bath tub 6, and a lid 44 for openably covering the upper opening of the bath tub 6. The bath tub 6 is provided with a stepped part 10 formed at the periphery of the upper opening of the bath tub 6, and the lid 44 is mounted on the stepped part 10. Accordingly, the decomposition of the stains of the feet or the like placed in the bath tub and the elimination of the bacilli therein can be carried out with water supplied into the bath tub. Water in the bath tub is prevented from spilling with the lid when the case of the main body is carried, and the floor or the like can be prevented from deterioration by discoloring due to the spilling of electrolytic water. The stepped part prevents water in the bath tub from spilling outside the bath tub when water in the bath tub tries to spill out of the bath tub through a gap between the mounting surface for the lid and the lid.