A magnetron which generates a high-frequency energy in the Terahertz band
is provided. The magnetron includes a cathode unit, which is connected to
a terminal of a power source, and which selectively emits an electron
according to when power is supplied; an anode block, which is connected
to another terminal of the power source, and which has an operation
chamber in which the emitted electron moves; and one or more resonance
cavities which generate a high-frequency energy by a movement of the
emitted electron; and a pair of magnet units forming a magnetic field in
the operation chamber.