To provide an irradiation part for a microwave therapeutic apparatus, performing a thermotherapy of an affected part regardless of a narrow area and a wide area and performing the effective thermotherapy while giving a superior warm sense to a patient.

The skeleton of the irradiation part 1 includes three or more, an odd-number of base bodies divided from each other and reflecting microwaves, the odd-number of base bodies are disposed adjacent to each other, and the adjacent base bodies are rotationally fixed and connected to each other. Among the odd-number of base bodies, the base body disposed at the center is provided with an antenna part. In order to obstruct the rotation of the base bodies, the respective base bodies are covered with a cover made of material quality to transmit the microwaves, and a light emitting part, which emits light on receiving the microwaves from the antenna part, is provided between the base bodies and the cover. A a person who gives medical treatment is given information to the effect that the microwaves are radiated form the antenna part. The antenna part is shaped to radiate the microwaves in the longitudinal direction and with an extent in the direction of arranging the base bodies.