PURPOSE: To eliminate the effect on a microwave characteristic due to the structure of a case by constituting a microwave integrated circuit storage space by an inner circumferential wall of a case, an upper cover and a microwave carrier and protecting the microwave carrier and the case by means of a plate spring member for the contact.

CONSTITUTION: The case 10 of a package is opened to upper and lower faces and has an internal space 11 with a rectangular step whose surrounding is closed and the space 11 consists of a lower space 12 whose width is large and an upper space 13 with a small width and the step 14 bordering both the spaces is two strips in parallel with each other. The microwave carrier 15 is a flat body and fitted to the face of the step 14 by a screw 16 to shut the upper space 13 and the lower space 12 through partition. The microwave base 17 is connected to the face (upper face) of the upper space 13 of the microwave carrier 15 while the microwave integrated circuit is taken as the upper face. The conductive plate spring member 18 is closed between the front end and the rear end of the case 10 and the microwave carrier 15 and screwed to the lower face of the microwave carrier 15.