To provide an anode structure for a magnetron, which is of a comparatively compact and lightweight construction while it can operate with a comparatively low frequency.

An anode structure for a magnetron is equipped with T-shaped anode vanes 3 each having a portion extending in the radial direction and a portion 3b extending in the circumferential direction, and the cylindrical surfaces 3c of the circumferential portions 3b are positioned confronting the cathode of the magnetron completed. Use of these T-vanes increases the inductance and allows emission of low frequency waves without increasing the dimensions of the magnetron, compared with a conventional one. At each end of the anode structure, two or more, preferably four, anode straps 5-8 are used to increase the capacitance, which allows a further decrease in the frequency. It is preferred that this anode structure is incorporated in a magnetron in which as high a magnetic field as approx. 500 Gauss is used for magnetron operating with 100 MHz. Further an anode shell 2 itself constitutes a magnetic field return path.