To provide a hot bath apparatus with a mixing function for sufficiently mixing a gas into liquid to be supplied to a bathtub.

The hot bath apparatus comprises: a mixing tub 20; a gas recovery tub 30 to which the liquid mixture of the liquid and the gas is supplied from the mixing tub 20; a bathtub 11 for arms and a bathtub 12 for legs to which the liquid mixture of the liquid and the gas is supplied from the gas recovery tub 30; a first conduit 71 for supplying the liquid mixture from the mixing tub 20 to the gas recovery tub 30; a second conduit 72 for supplying the liquid mixture from the gas recovery tub 30 to the bathtub 11 for arms; a recovery path 73 for recovering the liquid mixture from the bathtub 12 for legs to the mixing tub 20; and a gas recovery path 74 for supplying the gas which flows out from the liquid mixture in the gas recovery tub 30 to the recovery path 73. To the bathtub 12 for legs, the liquid mixture is supplied from the bathtub 11 for arms through an overflow pipe 75.