To provide a low-cost converter module comprising less number of components, related to a flip-chip mounted MMIC package where no cover is provided to each MMIC for mounting.

MMICs 2-4 are flip-chip mounted on a resin board 1 where a power supply IC14 is mounted on its lower surface. The entire substrate is mounted to a metal case 12 for air-tight sealing. So, no package is required for each MMIC, resulting in decreased number of components, less number of assembly processes, and less number of operation test processes. Thus, an MMIC package of lower price is obtained.