A semiconductor device includes: an channel layer formed on a semiconductor substrate; a drain electrode and a source electrode both formed on the channel layer apart from each other; a surface passivation film formed on the channel layer so as to cover the channel layer except for the drain electrode and the source electrode; a gate electrode disposed between the drain electrode and the source electrode so as to penetrate the surface passivation film; a field plate electrode provided on the surface passivation film between the drain electrode and the gate electrode at a predetermined distance from the gate electrode; and a connecting plate having a bridge structure connecting the gate electrode to the field plate electrode. The bridge structure may be formed with at least one opening penetrating the connecting plate so as to face the surface passivation film with a predetermined space.