An innovative photosensor using bioactivity unit as ultimate parts was developed. The use of photosynthetic protein, extracted from cyanobacteria living in a hot spring and characterized by 100% quantum yield of photo-electric conversion for red light, as a photoreceptor is promising way to achieve high-performance, no-heating and stable bionic-photosensor. The key-process for construction was as below; (1) extraction of protein with keeping their bioactivity, (2) direct connection of conductive molecular wire to electron relay system in photosynthetic protein (just like plugging) and (3) integration on semiconductor devices (FET). The work will be extended in future to the development of a bio-electronic imaging device with higher degree of integration, leading to the establishment of bio-electronic industrial technology and innovative materials science.