A magnetron capable of being efficiently assembled is provided. The magnetron includes a filament, a pair of shields, a pair of leads, a pair of connection plates, and a pair of terminal rods. The filament is coil-shaped. The shields are attached to both ends of the filament, respectively. The leads are attached to the shields at first ends of the leads, respectively. The connection plates are attached to second ends of the leads, respectively. The terminal rods are attached to the connection plates, respectively, to supply power to the leads through the connection plates, and have slender protrusions, which have sectional areas smaller than sectional areas of attachment portions of the terminal rods so that the terminal rods are attached to the connection plates with the slender protrusions passing through the connection plates.