Process and device for producing nanofiber

A process and a device for producing a nanofiber are provided in which a Taylor cone is stably maintained to improve the production efficiency. A solution (25) obtained by dissolving a cellulosic polymer in a solvent is sent out from the tip of a nozzle (13) while keeping the solution at a constant temperature in the range of 5-40°C, thereby forming a Taylor cone (44) at the tip orifice (13a). A voltage is applied between the solution (25) and a collector (50) by an electric power source (62) to eject a fiber as a spinning-solution jet (45) from the Taylor cone (44) to the collector (50). A cooling gas (43) supplied through a gas supply pipe (20) and having a constant temperature in the range of 5-15°C is sent to the periphery of the Taylor cone (44) through a gas supply slit (21), which is the space between the wall of the gas supply pipe (20) and the outer peripheral surface of the nozzle (13). Due to this, the evaporation of the solvent from the Taylor cone (44) is inhibited and the occurrence of droplets due to surface solidification and resultant skin formation is inhibited. Thus, production failures caused by the droplets are eliminated.