To provide a microwave feeding system in which the manufacturing cost is reduced by prolonging the service life of a magnetron oscillator and reducing the number of components.

A microwave feeding system is constituted of a single microwave feeding section composed of a magnetron 1 for generating microwave and a high-frequency coupler 3 coupled with the output of the magnetron 1 and a plurality of systems of microwave distributing sections 10 (1)-10 (N) respectively provided with circulators 41-4N and microwave switches 51-tN connected between the circulators 41-4N and microwave utilizing devices 71-7N. The circulator 41 of the section 10 (1) is connected to the coupler 3 and the circulator 42 of the section 10 (2) and similarly the circulator 42 is connected to the circulator 43 of the section 10 (3) of the next system. When the microwave switch of any one system of plural systems of the microwave distributing sections 10 (1)-10 (N) is selectively turned on, a microwave is selectively supplied only to the microwave utilizing device connected to the switch.