HIGH-FREQUENCY SEMICONDUCTOR PACKAGE

An input feedthrough (8) and an output feedthrough (9) provided on the substrate (3) are wire-connected to an input pad (5) and an output pad (6) of the semiconductor chip (4) respectively. A metal seal ring (12) is provided on the substrate (3) is electrically connected to the metal plate (1) by a through-hole (15). A conductive cap (14) is bonded to the metal seal ring (12) and covers a place above the semiconductor chip (4). Both ends of an isolation metal wire (13) are electrically connected to the metal plate (1) and a loop comes into contact with a lower surface of the conductive cap (14). The isolation metal wire (13) constitutes an isolation wall partitioning an inner space into a region including the input feedthrough (8) and a region including the output feedthrough (9).