PURPOSE: To provide a microwave treatment device capable of concentrically supplying a large electric power electromagnetic wave energy to a very small location to be treated, by equipping a microwave antenna with radial directivity to the periphery direction set on the tip of a coaxial cable, a microwave supply means and an observing means for the microwave antenna.

CONSTITUTION: This microwave treatment device is equipped with an applicator 1 for surgical treatment, a microwave relay cable 2, a microwave oscillator 3, and a foot switch 4. The applicator 1 for surgical treatment has an inserting part 5 composed of coaxial cable 6 and so as to be suitable for inserting into an organism, and an electrode 7 for a microwave antenna for supplying microwave energy to the organism is constituted at the tip of the cable 6. Since the electrode part 7 for the microwave antenna is provided by bending the tip part of the core conductor, it has anisotropic radiation directivity regarding to the periphery direction of the coaxial cable 6.