A spinneret comprising: a plate including a plurality of nozzle holes formed therein; or a plurality of the plates stacked one another in a spinning direction, wherein, in at least one of the plates, the plurality of nozzle holes are formed in a substantially rectangular area on a principal surface, nozzle hole rows are aligned at regular intervals in a long side direction of the rectangle, each of the nozzle hole rows including the plurality of nozzle holes aligned at regular intervals in a short side direction of the rectangle, the rectangular area includes a non-forming zone that intersects with the nozzle hole rows, the non-forming zone continuously extending from one long side of the rectangle to the other long side, and the non-forming zone including no nozzle holes, in nozzle hole rows with which the non-forming zone intersects out of the nozzle hole rows, in each of the nozzle hole rows, the nozzle hole is not formed on a part where the non-forming zone intersects with a position of the regular interval at which the nozzle holes are aligned, and the nozzle hole corresponding to number of the unformed nozzle holes is additionally formed in a short side direction of the nozzle hole row, and number of nozzle holes in all of the nozzle hole rows is identical. a plate including a plurality of nozzle holes formed therein; or a plurality of the plates stacked one another in a spinning direction, wherein, in at least one of the plates, the plurality of nozzle holes are formed in a substantially rectangular area on a principal surface, nozzle hole rows are aligned at regular intervals in a long side direction of the rectangle, each of the nozzle hole rows including the plurality of nozzle holes aligned at regular intervals in a short side direction of the rectangle, the rectangular area includes a non-forming zone that intersects with the nozzle hole rows, the non-forming zone continuously extending from one long side of the rectangle to the other long side, and the non-forming zone including no nozzle holes, in nozzle hole rows with which the non-forming zone intersects out of the nozzle hole rows, in each of the nozzle hole rows, the nozzle hole is not formed on a part where the non-forming zone intersects with a position of the regular interval at which the nozzle holes are aligned, and the nozzle hole corresponding to number of the unformed nozzle holes is additionally formed in a short side direction of the nozzle hole row, and the plurality of nozzle holes are formed in a substantially rectangular area on a principal surface, nozzle hole rows are aligned at regular intervals in a long side direction of the rectangle, each of the nozzle hole rows including the plurality of nozzle holes aligned at regular intervals in a short side direction of the rectangle, the rectangular area includes a non-forming zone that intersects with the nozzle hole rows, the non-forming zone continuously extending from one long side of the rectangle to the other long side, and the non-forming zone including no nozzle holes, in nozzle hole rows with which the non-forming zone intersects out of the nozzle hole rows, in each of the nozzle hole rows, the nozzle hole is not formed on a part where the non-forming zone intersects with a position of the regular interval at which the nozzle holes are aligned, and the nozzle hole corresponding to number of the unformed nozzle holes is additionally formed in a short side direction of the nozzle hole row, and number of nozzle holes in all of the nozzle hole rows is identical.