Abstract: A current-switching type compound semiconductor logic circuit which is high in an operating speed and low in power consumption. Voltage stabilizing transistors are provided to the logic circuit so that voltage signals which are in-phase with the gates of driving transistors and has a mean electric potential higher than that of the same by a predetermined value is applied to the gate thereof. The voltage stabilizing transistors act as a buffer to prevent electric potential of the driving transistors from fluctuating. As a result, it is possible to secure stable outputs in which the distortion of a waveform or the fluctuation of a cross point due to a jitter is hardly generated.