PURPOSE: To obtain a photoelectric transducer having fast response and enabling switch operation by two terminals with hysteresis to an optical input by composing the optoelectric transducer of a P-N junction light-receiving section region, a negative resistance section and a bias-voltage energizing section.

CONSTITUTION: An optoelectric transducer consists of a negative resistance section 1 having BAMBIT structure, a bias-voltage energizing section 2 and a light-receiving section region 3 as a photo-diode. A BAMBIT is composed of a P-base region 6, a P+ region 8, a P+ contact region 9, an emitter region 10 and a gate region 11 in the negative resistance section 1. On the other hand, the bias-voltage energizing section 2 contains resistance regions 12, 13, 14. The emitter region 10 is connected to the resistance region 13 by an emitter electrode 17 and a bonding pad 19, and the P+ contact region 9 is connected to the resistance region 14 by the base electrode 16 of the BAMBIT. The light-receiving section region 3 is bonded with the P+ contact region 9 and the resistance region 14 by the base region 16 of the BAMBIT.