The present invention relates to a half-body bath/sauna machine for activating blood circulation and the metabolism by warming the lower half of the human body by means of steam, and more particularly, to a steam warming half-body bath/sauna machine for warming the lower half of the human body with medicated steam to prevent and treat blood circulation disorders, metabolic functional disorders, gynecological disorders, stress, poor circulation, geriatric diseases, skin disorders and the like, by providing a sauna compartment that enables a user to sit comfortably with the lower half of the body (the legs) straightened, while medicated steam is uniformly fed into the sauna compartment from a steam device through a steam tube, and providing a cover panel integrally formed with an ingress/egress door of the sauna compartment. In addition, the steam warming half-body bath/sauna machine of the present invention is provided with said sauna compartment that enables a user to sit comfortably with the lower half of the body (the legs) straightened, a steam device configured for good steam generation, and a steam tube, which enable the uniform feeding of medicated steam into the sauna compartment, and the amount of steam generated by the steam device can be suitably controlled through precisely controlling the amount of water supplied to the steam device.