PURPOSE: To fix easily a circulator, by providing a magnetic substance attracted in a magnet mounting hole of a case adhering a microwave integrated circuit element to a magnet of the ≥2 of circulaters placed closely together.

CONSTITUTION: Screw threads for screws 19, 19' are threaded to holes 12, 12' mounting the magnet of the circulator of the case 5', and the screws 19, 19' made of a magnetic substance are screwed to the holes 12, 12'. The magnets 17, 18 of the circulators 13, 13' are attracted to the screws 19, 19'. A ground conductor 16 under other microwave integrated circuit elements 14, 15 is bonded to the case 5' and the upper conductor of each element is connected. Thus, the circulators 13, 13' are fixed and the manufacture of the microwave integrated circuit is made easily. Further, the screws 19, 19' are removed after the end of completion of manufacture.