PURPOSE: To make the integrated circuit small and to improve the isolation characteristic between circuits of the integrated circuit by connecting a stub made of a columnar metal onto a transmission line formed on a dielectric substrate perpendicular to the substrate.

CONSTITUTION: A columnar stub 40 made of Au or the like is formed on a transmission line 3 on a dielectric substrate 1 made of GaAs or the like in a direction perpendicular to the substrate 1. Thus, the isolation characteristic between circuits of the integrated circuit is improved and the integrated circuit is made small. Moreover, the same effect as the connection of a stub of an infinite length is obtained by fitting a radio wave absorbing body made of a magnetic body such as a ferrite to an upper end face of the stub 40.