The present invention relates to a half-body bath/sauna machine for activating blood circulation and 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 his or her body (the legs) straightened, while medicated steam is being uniformly fed into the sauna compartment from a steam device through a steam pipe, and by providing a cover panel integrally formed with an entrance/exit door for the sauna compartment.