Abstract: The invention disclosed relates to a bulk semiconductor device having a semiconductor element exhibiting a negative conductivity under a high electric field and being capable of generating a high electric field domain therein. The semiconductor device includes two ohmic electrodes disposed at opposite ends to apply a bias voltage, at least one means for generating a high electric field domain in the semiconductor device by means applying an input signal to the generating means, at least one means for inhibiting generation of a high electric field domain by means applying another input signal to the inhibiting means, and means for detecting the existence of the high electric field domain in the semiconductor device to produce an output signal.