To provide a magnetron having the same frequency characteristics between respective resonators by improving an asymmetric structure between the resonators.

This magnetron includes a filament 10 to emit thermoelectrons, a plurality of positive electrode vanes radially disposed around the filament, and an antenna 38 coupled with at least one positive electrode vane. On the positive electrode vane coupled with the antenna, an antenna coupling part 24 is provided, and for coupling the antenna to the positive electrode vane, the antenna coupling part is extended outward by a prescribed length from the end of the vane.