An apparatus for producing composite structure fibers is disclosed which includes an upper distribution plate provided with plural slits for making at least two spinning components into independent thin layer streams, a lower distribution plate provided with plural fine holes for dividing each of said thin layer streams into plural fine capillary streams independent from each other and a spinneret plate provided with a bundling space and extrusion orifices for bundling said previously divided fine capillary streams and extruding them into filaments, said upper distribution plate, lower distribution plate and spinneret plate being piled up in this order.