PROTEIN FIBER AND METHOD FOR PRODUCING SAME

This protein fiber contains silk fibroin, and the protein fiber has a stress of at least 450 MPa and a rupture elongation of at least 5%. This method for producing a protein fiber is for obtaining the aforementioned protein fiber, obtained by wet-spinning a doped liquid containing silk fibroin, and then performing at least heated stretching under dry heat on the un-stretched thread of protein fiber. The stretched thread or unstretched thread of the protein fiber may be further cross-linked by means of a carbodiimide. As a result, provided are: a protein fiber having high stress and a favorable rupture elongation and a method for producing same.