In a magnetron apparatus and a manufacturing method of the present invention, the magnetron apparatus comprises an anode cylinder, and a plurality of plate-form anode segments radially arranged around a central axis of the anode cylinder inside the anode cylinder. The anode segments are pressed against an inner surface of the anode cylinder by a pin press-fit into the central portion of the anode cylinder, and a far-end-side end surface each of the anode segments is secured to the inner surface. A concave is provided in the central portion of an inner end surface where the anode segments come into contact with the pin.