To provide a polyamide stable fiber which has good dispersibility, when a nonwoven fabric or a paper yarn fabric is obtained therefrom, by preventing fusion of yarn threads of the fiber with one another in production processes, nor fusion between the yarn threads caused by turbulence or entanglement of the bundle of the yarn threads, and from which the nonwoven fabric or the paper excellent in both of quality and performance is obtained.

This polyamide stable fiber is formed so that at least surfaces of the fiber are made up by a polyamide component containing 0.005-0.5 mass % of a bisamide compound and a fiber length thereof is 0.1-50 mm. A copolymer containing at least two components selected from nylon 6, nylon 66, nylon 12, nylon 46, and nylon 610 components is preferably used as the polyamide component containing 0.005-0.5 mass % of the bisamide compound in the polyamide staple fiber.