Abstract: A method for producing ultrafine fibers of the present invention includes forming an electric field between an discharging nozzle from which a raw resin is discharged and a charging electrode which is disposed apart from the discharging nozzle, and supplying the raw resin which has been heated and melted into the electric field from the discharging nozzle to spin the raw resin. The raw resin is a resin mixture which contains a resin having a melting point and an additive, and satisfies a relation (I) below: A/B?1.0×102??(I) wherein A represents the absolute value (?) of electrical impedance of the raw resin at 50° C., and B represents the absolute value (?) of electrical impedance of the raw resin at a temperature 50° C. higher than a melting point of the raw resin.

Abstract: A method for producing ultrafine fibers of the present invention includes forming an electric field between an discharging nozzle from which a raw resin is discharged and a charging electrode which is disposed apart from the discharging nozzle, and supplying the raw resin which has been heated and melted into the electric field from the discharging nozzle to spin the raw resin. The raw resin is a resin mixture which contains a resin having a melting point and an additive, and satisfies a relation (I) below: A/B?1.0×102 ??(I) wherein A represents the absolute value (?) of electrical impedance of the raw resin at 50° C., and B represents the absolute value (?) of electrical impedance of the raw resin at a temperature 50° C. higher than a melting point of the raw resin.