A high pressure condenser for a magnetron, in which a pair of dielectric ceramics having an arch shape are separated from each other, central conductors are connected to internal peripheries of the dielectric ceramics, and a ground metal is connected to external peripheries of the dielectric ceramics, thereby not requiring any additional structure for connecting the dielectric ceramics and the central conductors, simplifying the structures of the central conductors, and reducing the quantity of the dielectric ceramics needed in proportion to the separation interval between the dielectric ceramics.