PURPOSE: To obatain electrically conductive unconventional polyamide fiber excellent in designability having electric conductivity due to copper sulfide imparted thereto without introducing cyano group thereinto and having a complex color formed from a color by dyeing and a color of the copper sulfide.

CONSTITUTION: Electric conductivity is imparted to polyamide fiber by bounding and/or copper sulfide and metallic copper to the polyamide fiber or polyamide fiber dyed with an acid dye is treated with an aqueous solution of polyethylenemine, and then with an aqueous solution of a cupric inorganic salt and an aqueous solution of a sulfur-releasing reducing agent to bond and/or deposit the copper sulfide and metallic copper on the polyamide fiber. Thereby, the objective electrically conductive polyamide fiber having the electric conductivity impared thereto is obtained.