an improved construction of a through - type capacitor suitable for used with a magnetron is disclosed . the through - type capacitor comprises a dielectric member formed with a through hole at the center thereof , a central conductor inserted into the through hole , and electrodes formed on the outer peripheral surface of the dielectric member and the inner peripheral surface of the through hole . the electrode on the inner peripheral surface of the through hole is connected by solder to the central conductor . the central conductor and the dielectric member have a portion free of solder therebetween in which the solder is expandable .