An amplifier GaAs MMIC for microwave band applications includes a ground electrode 8 having a via hole group 12 composed of three via holes 11 filled with plated metals 10a that are formed adjacently. The interaction thereby generates high frequency electromagnetic bonding, which reduces the ground inductance. According to the MMIC, the ground inductance of the via hole may be reduced while decrease of a strength and increase of a size being restrained.